Is Most Published Research Wrong?

In 2011 an article was published in the reputable "Journal of Personality and Social Psychology". It was called "Feeling the Future: Experimental Evidence for Anomalous Retroactive Influences on Cognition and Affect" or, in other words, proof that people can see into the future. The paper reported on nine experiments. In one, participants were shown two curtains on a computer screen and asked to predict which one had an image behind it, the other just covered a blank wall. Once the participant made their selection the computer randomly positioned an image behind one of the curtains, then the selected curtain was pulled back to show either the image or the blank wall the images were randomly selected from one of three categories: neutral, negative, or erotic. If participants selected the curtain covering the image this was considered a hit.

Now with there being two curtains and the images positions randomly behind one of them, you would expect the hit rate to be about fifty percent. And that is exactly what the researchers found, at least for negative neutral images however for erotic images the hit rate was fifty-three percent. Does that mean that we can see into the future? Is that slight deviation significant? Well to assess significance scientists usually turn to p-values, a statistic that tells you how likely a result, at least this extreme, is if the null hypothesis is true. In this case the null hypothesis would just be that people couldn't actually see into the future and the 53-percent result was due to lucky guesses. For this study the p-value was .01 meaning there was just a one-percent chance of getting a hit rate of fifty-three percent or higher from simple luck. p-values less than .05 are generally considered significant and worthy of publication but you might want to use a higher bar before you accept that humans can accurately perceive the future and, say, invite the study's author on your news program; but hey, it's your choice.

After all, the .05 threshold was arbitrarily selected by Ronald Fisher in a book he published in 1925. But this raises the question: how much of the published research literature is actually false? The intuitive answer seems to be five percent. I mean if everyone is using p less than .05 as a cut-off for statistical significance, you would expect five of every hundred results to be false positives but that unfortunately grossly underestimates the problem and here's why. Imagine you're a researcher in a field where there are a thousand hypotheses currently being investigated. Let's assume that ten percent of them reflect true relationships and the rest are false, but no one of course knows which are which, that's the whole point of doing the research. Now, assuming the experiments are pretty well designed, they should correctly identify around say 80 of the hundred true relationships this is known as a statistical power of eighty percent, so 20 results are false negatives, perhaps the sample size was too small or the measurements were not sensitive enough. Now considered that from those 900 false hypotheses using a p-value of .05, forty-five false hypotheses will be incorrectly considered true.

As for the rest, they will be correctly identified as false but most journals rarely published no results: they make up just ten to thirty percent of papers depending on the field, which means that the papers that eventually get published will include 80 true positive results: 45 false positive results and maybe 20 true negative results. Nearly a third of published results will be wrong even with the system working normally, things get even worse if studies are underpowered, and analysis shows they typically are, if there is a higher ratio of false-to-true hypotheses being tested or if the researchers are biased. All of this was pointed out in 2005 paper entitled "Why most published research is false". So, recently, researchers in a number of fields have attempted to quantify the problem by replicating some prominent past results. The Reproducibility Project repeated a hundred psychology studies but found only thirty-six percent had a statistically significant result the second time around and the strength of measured relationships were on average half those of the original studies.

An attempted verification of 53 studies considered landmarks in the basic science of cancer only managed to reproduce six even working closely with the original study's authors these results are even worse than i just calculated the reason for this is nicely illustrated by a 2015 study showing that eating a bar of chocolate every day can help you lose weight faster. In this case the participants were randomly allocated to one of three treatment groups: one went on a low-carb diet, another one on the same low carb diet plus a 1.5 ounce bar of chocolate per day and the third group was the control, instructed just to maintain their regular eating habits at the end of three weeks the control group had neither lost nor gained weight but both low carb groups had lost an average of five pounds per person the group that a chocolate however lost weight ten percent faster than the non-chocolate eaters the finding was statistically significant with a p-value less than .

05 As you might expect this news spread like wildfire, to the front page of Bild, the most widely circulated daily newspaper in Europe and into the Daily Star, the Irish Examiner, to Huffington Post and even Shape Magazine unfortunately the whole thing had been faked, kind of. I mean researchers did perform the experiment exactly as they described, but they intentionally designed it to increase the likelihood of false positives: the sample size was incredibly small, just five people per treatment group, and for each person 18 different measurements were tracked including: weight, cholesterol, sodium, blood protein levels, sleep quality, well-being, and so on; so if weight loss didn't show a significant difference there were plenty of other factors that might have. So the headline could have been "chocolate lowers cholesterol" or "increases sleep quality" or… something. The point is: a p-value is only really valid for a single measure once you're comparing a whole slew of variables the probability that at least one of them gives you a false positive goes way up, and this is known as "p-hacking". Researchers can make a lot of decisions about their analysis that can decrease the p-value, for example let's say you analyze your data and you find it nearly reaches statistical significance, so you decide to collect just a few more data points to be sure then if the p-value drops below .

05 you stop collecting data, confident that these additional data points could only have made the result more significant if there were really a true relationship there, but numerical simulations show that relationships can cross the significance threshold by adding more data points even though a much larger sample would show that there really is no relationship. In fact, there are a great number of ways to increase the likelihood of significant results like: having two dependent variables, adding more observations, controlling for gender, or dropping one of three conditions combining all three of these strategies together increases the likelihood of a false-positive to over sixty percent, and that is using p less than .05 Now if you think this is just a problem for psychology neuroscience or medicine, consider the pentaquark, an exotic particle made up of five quarks, as opposed to the regular three for protons or neutrons.

Particle physics employs particularly stringent requirements for statistical significance referred to as 5-sigma or one chance in 3.5 million of getting a false positive, but in 2002 a Japanese experiment found evidence for the Theta-plus pentaquark, and in the two years that followed 11 other independent experiments then looked for and found evidence of that same pentaquark with very high levels of statistical significance. From July 2003 to May 2004 a theoretical paper on pentaquarks was published on average every other day, but alas, it was a false discovery for their experimental attempts to confirm that theta-plus pentaquark using greater statistical power failed to find any trace of its existence. The problem was those first scientists weren't blind to the data, they knew how the numbers were generated and what answer they expected to get, and the way the data was cut and analyzed, or p-hacked, produced the false finding. Now most scientists aren't p-hacking maliciously, there are legitimate decisions to be made about how to collect, analyze and report data, and these decisions impact on the statistical significance of results.

For example, 29 different research groups were given the same data and asked to determine if dark-skinned soccer players are more likely to be given red cards; using identical data some groups found there was no significant effect while others concluded dark-skinned players were three times as likely to receive a red card. The point is that data doesn't speak for itself, it must be interpreted. Looking at those results it seems that dark skinned players are more likely to get red carded but certainly not three times as likely; consensus helps in this case but for most results only one research group provides the analysis and therein lies the problem of incentives: scientists have huge incentives to publish papers, in fact their careers depend on it; as one scientist Brian Nosek puts it: "There is no cost to getting things wrong, the cost is not getting them published". Journals are far more likely to publish results that reach statistical significance so if a method of data analysis results in a p-value less than .

05 then you're likely to go with that method, publication's also more likely if the result is novel and unexpected, this encourages researchers to investigate more and more unlikely hypotheses which further decreases the ratio of true to spurious relationships that are tested; now what about replication? Isn't science meant to self-correct by having other scientists replicate the findings of an initial discovery? In theory yes but in practice it's more complicated, like take the precognition study from the start of this video: three researchers attempted to replicate one of those experiments, and what did they find? well, surprise surprise, the hit rate they obtained was not significantly different from chance. When they tried to publish their findings in the same journal as the original paper they were rejected. The reason? The journal refuses to publish replication studies. So if you're a scientist the successful strategy is clear and don't even attempt replication studies because few journals will publish them, and there is a very good chance that your results won't be statistically significant any way in which case instead of being able to convince colleagues of the lack of reproducibility of an effect you will be accused of just not doing it right.

So a far better approach is to test novel and unexpected hypotheses and then p-hack your way to a statistically significant result. Now I don't want to be too cynical about this because over the past 10 years things have started changing for the better. Many scientists acknowledge the problems i've outlined and are starting to take steps to correct them: there are more large-scale replication studies undertaken in the last 10 years, plus there's a site, Retraction Watch, dedicated to publicizing papers that have been withdrawn, there are online repositories for unpublished negative results and there is a move towards submitting hypotheses and methods for peer review before conducting experiments with the guarantee that research will be published regardless of results so long as the procedure is followed. This eliminates publication bias, promotes higher powered studies and lessens the incentive for p-hacking. The thing I find most striking about the reproducibility crisis in science is not the prevalence of incorrect information in published scientific journals after all getting to the truth we know is hard and mathematically not everything that is published can be correct.

What gets me is the thought that even trying our best to figure out what's true, using our most sophisticated and rigorous mathematical tools: peer review, and the standards of practice, we still get it wrong so often; so how frequently do we delude ourselves when we're not using the scientific method? As flawed as our science may be, it is far away more reliable than any other way of knowing that we have. This episode of veritasium was supported in part by these fine people on Patreon and by Audible.com, the leading provider of audiobooks online with hundreds of thousands of titles in all areas of literature including: fiction, nonfiction and periodicals, Audible offers a free 30-day trial to anyone who watches this channel, just go to audible.com/veritasium so they know i sent you. A book i'd recommend is called "The Invention of Nature" by Andrea Wolf which is a biography of Alexander von Humboldt, an adventurer and naturalist who actually inspired Darwin to board the Beagle; you can download that book or any other of your choosing for a one month free trial at audible.

com/veritasium so as always i want to thank Audible for supporting me and I really want to thank you for watching..

Do the Math – The Movie

Like most people, I'm not an activist by nature. There's really not that many people whose greatest desire it to go out and fight the system. My theory of change was I'll write my book, people will read it and they'll change. But that's not how change happens. So I've been kind of forced to go against my sense of who I am most comfortable being. It seems like it's the things that's required now and I think it's probably required that an awful lot of us doing things that are a little hard for us, make a little noise, be a little uncomfortable, push other people to be a little uncomfortable. This is really the fight of our time. It's official: 2012 was the hottest year in the United States since weather scientists started keeping records. 2012 was not only the warmest year on record, but also the second most extreme, featuring tornadoes, wild fires, a massive drought. Rising seas due to climate change. Heat trapping gases from burning oil, coal and gas.

10.9 billion dollars in profits, people look at this and say that's a world turned upside down. Listening to your testimony makes me even more convinced that we need to act to prevent cataclysmic climate change. BP cut corner after corner and now the whole gulf coast is paying the price. How can you justify the record profits you're making? Well our business is one of very large numbers. Okay, let's bring out Bill, he's an environmentalism and president and co-founder of 350.org. And my guest Bill McKibben, our nation's leading environmentalist. We started this thing called 350.org. We're going out and building the kind of political movement that will change things. We just announced this road show out across the country to really try take it at the fossil fuel industry. People are just lining up to try and get involved in this fight. Well, thank you all, thank you all so much for being here today. It is a great pleasure for me to get to be here tonight and one of the gifts for me of these last few months was getting, tiring as it was in a sense, to travel around the country. And one of the things that was great was just being reminded was what an incredibly beautiful place this is.

You know, we got to Denver and it was gorgeous but the air was full of smoke from fires still burning in December after the biggest fire season ever and we got through this gorgeous farmland, much of it still-60% of it still in a federally declared drought. But it's also worth just saying that it's a terrible thing to take a world this beautiful and, for the sake of outsized profits for a few people for a little while, lay it to waste. Tonight's the start of the last campaign I may really get to fight. Not 'cause I'm getting tired but because the planet's getting tired. In the world that we've built where our institutions aren't working the way they should, we have to do more than we should. That news doesn't depress me. In a sense it excites me, because I think we know what we need to do. I think we've peeled away the layers of the onion. We've got to the very heart of things.

As of tonight, we're taking on the fossil fuel industry directly. The moment has come where we have to take a real stance, we're reaching limits. The biggest limit that we're running into may be that we're running our of atmosphere into which to put the waste products of our society, particularly the carbon dioxide that is the ubiquitous biproduct of burning fossil fuels. You burn coal or oil or gas, you get CO2 and the atmosphere is now filling up with it. We know what the solutions for dealing with this trouble are, many of the technologies we need to get off fossil fuel and onto something else. The thing that is preventing us from doing it is the enormous political power wielded by those who have made and are making vast windfall profits off of fossil fuels. Well, there have been a lot of efforts by scientists to try to estimate whether we are living sustainably in the sense of whether we're consuming planetary resources at a rate that can be continued. The threat that this combination that climate change, water shortages, food shortages and rising energy prices is enormously troubling to anyone who's aware of the data and the way these issues could play out.

You can't keep increasing your economy infinitely on a finite planet. One of the things that humanity is facing is the need to dramatically reduce its carbon footprint over the next 40 years. And we're talking in the wealthy countries about 80 to 90% reductions. We're no longer at the point of trying to stop global warming. Too late for that. We're at the point of trying to keep it from becoming a complete and utter calamity. We shouldn't have to be here tonight. If the world worked in a kind of rational way, we shouldn't have to be here. 25 years ago our scientists started telling us about climate change. I played my small role in that by writing the first book about all this in 1989 for a general audience, a book called The End of Nature. If the world worked as it should, our leaders would have heeded those warning, gone to work, done the sensible things that at the time would have been enough to get us a long way to where we needed to go.

They didn't. And that's why we're in the fix we're in. This is the biggest emergency the human family has faced since it came out of the caves. There is nothing bigger. All these issues matter: immigration and health care and education. But this one is really about the physical change of the planet. We all have been saying we need to save the planet. But as I think about it, the planet's going to be around for some time to come. What's at stake now is civilization itself. Our most important climatologist, Jim Hansen, has his team at NASA do a study to figure out how much carbon in the atmosphere was too much. The paper they published may be the most important scientific paper of the millenium to date, said we now know enough to know how much is too much. Any value for carbon in the atmosphere greater than 350 parts per million is not compatible with the planet on which civilization developed and to which life on earth is adapted.

That's pretty strong language for scientists to use. Stronger still if you know that outside today, the atmosphere is 395 parts per million CO2. And rising at about 2 parts per million per year. Everything frozen on earth is melting. The great ice sheet of the arctic is reduced by more than half, the oceans are about 30% more acidic than they were 30 years ago because the chemistry of sea water changes as it absorbs carbon from the atmosphere. And because warm air holds more water vapor than cold, the atmosphere is about 5% wetter than it was 40 years ago. That's an astonishingly large change. There's more energy coming in and being absorbed by the earth than there is heat being radiated to space, which is exactly what we expected because as we add greenhouse gases to the atmosphere, it traps heat. Now we can measure that and that's the basis by which we can prove that the human made impacts on atmospheric composition are the primary cause of the climate change that we're observing. So let's get to work. We're calling this Do the Math and we're gonna do some math for a moment. Just three numbers, okay? I wrote about them in a piece last summer for Rolling Stone.

A piece that went oddly viral. It was the issue with Justin Bieber on the cover, but here's the strange thing: The next day I got a call from the editor saying, "Your piece has gotten ten times more likes on Facebook than Justin Bieber's." Some of that is doubtless the result of my sort of soulful stare, you know. But mostly it's because we managed to just kind of lay out this math in a very straight forward way that people needed to understand as we were going through what turned out to be the hottest year that America has ever experienced. Before we get to those three numbers, here's where we are so far: We've burned enough coal and gas and oil to raise the temperature of the earth one degree. What has that done? There was a day last September when the headline in the paper was "Half the Polar Ice Cap is missing." Literally. I mean if Neil Armstrong were up on the moon today, he'd look down and see half as much area of ice in the arctic. We've taken one of the largest physical features on earth and we have broken it. Shall we work through the numbers? There are three, and they're easy.

The first one's 2 degrees. That's how much the world has said it would be safe to let the planet warm. In political terms, it's the only thing that anybody's agreed to. Some of you may remember that climate summit in Copenhagen. There was only one number in the final two page voluntary accord that people signed. Only one number in it: 2 degrees. Every signatory pledged to make sure the temperature wouldn't rise about that. The EU, Japan, Russia, China, countries that make their money selling oil like the United Arab Emirates, the most conservative, recalcitrant, reluctant countries on earth. Even the United States. If the world officially believes anything about climate changes it's that 2 degrees is too much. Second number that scientists have calculated is how much carbon we can pour into the atmosphere and have a reasonable chance of staying below two degrees. They say about 565 more gigatons. A gigaton is a billion tons.

That's not a perfect chance, that's worse odds than Russian roulette, you know. Sounds like is should – it is a lot, 565 billions tons of CO2. The problem is we pour 30 billion tons a year now and it goes up 3% a year. Do the math and it's about 15 years before go past that threshold. So that's sobering news. But the scary number is the third number. The third number was the important one and the new one and it came from a team of financial analysts in the United Kingdom. And what they did was sit down with all the annual reports and SEC filings and things to figure out how much carbon the world's fossil fuel industry, how much they had already in their reserves and that number turned out to be 2795 gigatons worth of carbon. Five times as much as the most conservative governments on earth think would be safe to pour into the atmosphere. It's not even close. I mean, it's five times more.

Once you know that number, then you understand the essence of this problem. What the fossil fuel industry is doing is locking us into a future that we can't survive, that humanity cannot survive. And we know this because just at the end of 2012 we heard this from three different conservative sources simultaneously: The World Bank, The International Energy Agency, Price Waterhouse Cooper, hardly a hippy outfit. All told us that if we do nothing but more of the same, if we dig up those reserves, we are headed toward 4-6 degrees warming celsius. These numbers show, and I want to be absolutely clear here, these companies are a rogue force, they're outlaws. They're not outlaws against the laws of the state.

They get to write those for the most part. But they're outlaw against the laws of physics. If they carry out their business plan, the planet tanks. We have all the engineers and entrepreneurs we need. The thing that's hold us back above all else is the simple fact that the fossil fuel industry cheats. Alone among industries, they're allowed to pour out their waste for free. Nobody should be able to pollute for free. You can't, I can't. We can't walk out of here and go litter for free. If you do, you get a fine. If you run a small business, you can't just dump the garbage in the road, you've got to pay to have it hauled away or you get a fine. The only people who can pollute for free are these megapolluters when it comes to carbon: big oil, big coal. If you get a $25 fine for littering, you're going to pay $25 more than all of the industrial polluters have ever paid in 150 years for the carbon they've been dumping. That's how whack this whole thing is.

It's almost how we define civilization. You pick up after yourself unless you're the fossil fuel industry. Then you pour that carbon into the atmosphere for free and that is the advantage that keeps us from getting renewable energy at the pace that we need. We should internalize that externality. The only reason we haven't is because it would impair somewhat the record profitability of the fossil fuel industry and so they have battled at every turn to keep it from happening. These are rogue companies now. Once upon a time, they performed a useful social function. For a long time, the US's engine was fossil fuels like oil and coal to power trains, to power cars, to power industry. In the mid 1900's we realized there were consequences. If you look at industries like coal now, we just did a report with Harvard Medical School that showed that if they actually paid for what they're doing to us, what we're paying indirectly for that electricity, coal would cost anywhere from 3 to far more times their current cost.

They would be out of business and that is just, financially and morally, bankrupt. When a utility burns coal, it is the cheapest source of fuel, but they're not paying the full price. The externalities, the additional costs to society, to human health, to the environment, are not factored in as a cost of doing business. We subsidize the fossil fuel industries. We are paying them to continue to keep polluting and this means all kinds of things: it's tax breaks, it's loans, it's the fact that armies protect their pipelines and protect their trade routes. You're helping them stay on top and preventing their competitors like renewable fuels from competing. What we need is a level playing field. We could be using that public money, tax-payer money, to make the shift to green energy. Occasionally they will pretend to be seeing the light.

Ten years ago, BP announced that their initials now stand for Beyond Petroleum and they got a new logo and put some solar panels on some gas stations and they invested a tiny bit of money, a pittance in solar and wind research. Even that proved too much, three years ago they sold off those divisions and said that from now on they were going to concentrate on their core business. Which turned out to be basically wrecking the Gulf of Mexico. Why are they so fixated on hydrocarbons? Because these are the most profitable enterprises in human history. The top five oil companies last year made 137 billion dollars. That's 375 million dollars every day. That's a lot of money. They got 6.6 million dollars in federal tax breaks daily. They spent $440,000 a day lobbying congress.

Rex Tillerson, the head of Exxon, made $100,000 a day. Which, by the way, one of my favorite talking points is that climate scientists make up their findings because they're in it for the grant money, okay. The only problem that these companies have now is that the scientists are watching in real time while they pull off this heist and it's getting harder to deny. In fact, they're being to kind of admit what's going on. Last summer, for the very first time, the CEO of Exxon, Mr. Tillerson gave a speech in which he said, yes, it's true. Global warming exists. Clearly there's gonna be an impact so I'm not disputing that increasing CO2 emissions is going to have an impact. It'll have a warming impact. But since the only way to stop that would be to take a hit to the company's profitability, he immediately tried to change the subject.

It's an engineering problem and it has engineering solutions. Really? What kind of engineering solutions were you thinking? Changes to weather patterns that move crop production areas around, we'll adapt to that. Look, I mean all respect, but that's crazy talk. We can't move crop production areas around, okay. Crop production areas are what people in Vermont refer to as farms, okay. We already have farms every where that there is decent soil on earth. It is true that Exxon has done all it can to melt the tundra, but that does not mean that you can just move Iowa up there and start over again. There is no soil. If fossil fuel companies want to change, here's how we'd know they're serious: One, they'd need to stop lobbying in Washington. Two, they'd need to stop exploring for new hydrocarbons. The first rule of holes is that when you are in one, stop digging, okay.

And the third thing they'd need to do is go to work with the rest of us to figure out the plan where they turn themselves into energy companies, not fossil fuel companies and figure out with the rest of us how to keep 80% of those reserves underground. The thing that really does make this almost pathological is the fact that when we already have almost five times as much carbon as we can possibly burn, I mean Exxon alone: 100 million dollars a day exploring for new hydrocarbons. By this point we're scraping the bottom of the barrel. I mean we're in tar sands, we're doing shale oil, we're doing fracking, we're doing mountain top removal, we're doing deep sea drilling, we're taking apart the earth to look for the last bits of gas and oil and coal. I find that when I get depressed, the best antidote by far is action and I think that that's true for most people.

The problem with climate change is that it seems too big for any of us ourselves to take on. And ideed it is. It's only when we're working with other people, as many other people as possible, that we have any hope. So that's why I spend my time trying to build movements. I think it's the only chance we've got. Anybody can get involved. There's always stuff to be done and more of it all the time. That's what movements look like. We started 350.org in 2008 and when I say we I mean me and seven undergraduates at Middlebury College. We had the deep desire to try and do some global organizing about the first really global problem this planet's ever faced. And we spread out around the planet and for the next year or so we found people all over this earth who wanted to work with us. We asked them all to take one day and this was our first big day of action was in the fall of 2009. We said, Will you all join us for one day? Will you do something on that day to take this most important number, 350, and drive it into the information bloodstream of the planet? For the next 48 hours, pictures just poured in many a minute.

Before it was over, there'd been 5200 demonstrations in 181 countries. CNN called it the most widespread day of political activity in the planet's history. Cities across the globe have gathered today to rally for solutions to climate change. Locations around the globe. Hundreds of environment campaigners gathered in Edinborgh today. So we've gone on since then to do more of these big days of action. We work in every country but North Korea. We have had about 20,000 rallies or so. And we've gone on to do more direct things: spearhead the fight against the Keystone Pipeline, organize the largest civil disobedience action in thirty years. Now the high stakes battle over whether the Obama administration should approve a major oil pipeline bisecting the US. It would transfer tar sands from Alberta, Canada down to the Gulf of Mexico. The type of oil the pipeline would carry is far more toxic. Among the dirtiest of all fossil fuels.

This pipeline has proven to be very controversial. To the federal government to decide whether or not to give Keystone XL the green light. Tar sands is destructive in and of itself but it's also symbolic of a way of developing, a way of growing our economy that just can't be sustained. Right now a company called TransCanada has applied to build a new pipeline to speed more oil from Cushing to state-of-the-art refineries down in the Gulf Coast and today I'm directing my administration to cut through the red tape, break through the bureaucratic hurdles and make this project a priority. August was the beginning of the people's veto of this whole proposal. We will never give up until the very idea of Keystone XL is dead and buried. Tar sands are the turning point in our fossil fuel addiction. The fundamental fact is that as long as fossil fuels are the cheapest energy, they will continue to be used. The solution is to begin to put a price on carbon emissions. We the American people should not have to sacrifice our land and water to meet TransCanada's bottom line. We stand here right now because we are at our lunch counter moment for the twenty-first century.

President Obama, do the right thing. We are at a tipping point in America's history for this environmental movement. If you are going to be risking arrest, you're going to be lining up on this sidewalk. When I saw the acts of civil disobedience in front of the White House, people saying I will not let this Keystone pipeline be built, I won't let us be committed to an energy plan based on fossil fuels. You know the people who got arrested in front of the White House, those were not all people who were all self-identified as environmentalists. Those were farmers and ranchers, those were people from indigenous communities, those were business leaders, those were grandparents and moms and dads. We're really starting to see an expansion of the group of people that are fighting this fight, but we have a lot further to go on that. I've been forced to do things I didn't imagine I'd ever do: stand up on a stage in front of thousand of people, go to jail.

We're probably not going to be able to stop them all one pipeline, one mine at a time. We're also going to have to play, you know, offense. We think one thing the fossil fuel industry cares about is money so that's what we're going to go after. You want to take away our planet and our future? We're going to try and take away your money. We're going to try and tarnish your brand. This industry has behaved so recklessly that they should lose their social license, their veneer of respectability. We need these guys to be understood as those outlaws against the laws of physics. We need to take away some of their power and there's a lot of ways we're going to do it. One tool, the first tool, is divestment. We're going to ask or demand that institutions like colleges or churches sell their stock in these companies. The logic could not be simpler: If it's wrong to wreck the climate, it's wrong to profit from that wreckage.

That argument has worked in a big way exactly once in US history. There has been scattered violent incidence in the Athlone mixed race neighborhood. Authorities returned fire without warning. Organized, vocal and committed students urge the university to divest itself of all investments in South Africa. That's what happened during the fight against South African Apartheid. At 155 colleges and universities, people convinced their boards of trustees to sell their stock. And when Nelson Mandela got out of prison, one of his first trips was to the US and he didn't go first to the White House, he went to Berkley to say thank you to the University of California students who had forced the sale of 3 billion dollars worth of Apartheid tainted stock. Here's what we demand: One, no new investments in fossil fuel companies. Two, a firm pledge over the next five years that they will wind down their current positions.

It's not unreasonable. It's hard but it's not unreasonable. I'll give you a piece of news: The first college in the country to divest all its stock from fossil fuel companies was a college in Maine called Unity College with a 13 million dollar endowment. And none of that 13 million dollars at this point is in fossil fuels any place. Divestment really in one sense was a no brainer for us. When you look at other institutions and their struggle with whether or not to divest, it really boils down to one simple thing: willingness. The mayor in Seattle, he said, I spent the afternoon with my treasurer and we're figuring out how we're going to get the city's funds out of fossil fuel companies. Welcome everyone to our event tonight: Divesting from Fossil Fuels, a conversation with students from Barnard, Columbia, the New School, NYU and Hunter College. Students are asking for divestment. The fact that we have over 250 movements on different campusus around the country means that we have severely challenged that veneer of social respectability. They understand, like the religious denominations and cities that are also doing this, they understand what those numbers mean.

It's inconsistent with the reason these institutions exist for them to continue to invest in something that is dedicated to the destruction of civilization. We're asking the administration at NYU to divest the university endowment from the fossil fuel industry. We can re-invest in our antiquated infrastructure and make our buildings more energy efficient. People are always looking for this silver bullet, instead its the silver buckshot. How this campaign fits into the greater scheme of things is that this is just one of those ways in which we can take action. These are the kind of solutions that the university should be leading on and they should be saying, we're going to take the money that's piled up in our endowment that right now is either doing nothing or doing harm and we're going to take that money away from the problem makers and give it to the problem solvers. Once you know what's evil, now if you're ignorant you get a pass, but once you know what's evil, you have a moral responsibility to withdraw your energy from it.

We are participating in the destruction of our own world even if we don't want to because the fossil fuel industry is so intertwined in so many aspects in American life. They rely on our cooperation to continue what they're doing. But what if we said no? The divestment work is a piece of that and what it does is it has the ambition of transforming hundreds, thousands of institutions in the US to be allies rather than adversaries. We, as everyday people, have so much power. If you are a member of a church, you have the ability to work with your fellow congregants to make sure your church is not investing in fossil fuel companies. If you are a student on a college campus, not only do you have the opportunity, I think you have the responsibility to work with your fellow students to make sure that your institution of higher learning is not investing its endowment in the companies that are destroying your future and this planet. We have to send a message, a very clear message, to big oil, big energy that we are going to hold them liable and we are going to divest if they won't themselves being to change.

There is nothing, and I mean nothing, radical in what we are talking about here. All we're asking for when we talk about climate change is a planet that works the way that it did for the last 10,000 years, a planet that works the way the one we were born onto works. That's not a radical demand. That's, if you think about it, a conservative demand. Radicals work at oil companies. If you wake up in the morning to make your $100,000 a day, you're willing to alter the chemical composition of the atmosphere, then you're engaged in a more radical act than anyone who ever came before you. And our job is to figure out how to check that radicalism, how to bring it to heel, how to keep it from overwhelming everything good on this planet. And here's the good news, since I've been giving you lots of bad news, here's the good news: There's plenty we can do. The long-term solution to climate change is very clear.

We need to make the leap to renewable energy and we need to do it quickly, which will be hard. It will be the hardest thing we've done since gearing up to fight World War II or something but it's by no means impossible. When I feel a little overwhelmed with all the things we need to do, I go back and re-read the economic history of World War II. It was just a matter of months, you know, from the US automobile industry producing cars to tanks and planes and ships. It didn't take decades to restructure the US industrial economy. It didn't take years. It was done in a matter of months. And if we could do that now then certainly we can restructure the world energy economy over the next decade. And it's going to require some hard choices. It's going to require a real change in how we get our energy and how we move around. But the good news is that we have the solutions. You know, we have the ways.

We know what we need to do to get to a world where we're not buring as many fossil fuels. Why would we build a thousand mile pipeline taking almost a million barrels of oil from the most carbon intensive fuel source on the planet when wind energy is a whole lot cheaper and a whole lot cleaner? Why would be drill in the arctic when we know that solar power can meet our energy needs across the country? Why would be frack our countrysides and our watersheds when we know that energy efficiency would save more energy than natural gas can provide? I think that we're coming to that point now where extreme energy sources are so bad that the questions and these challenges are going to become easier and easier. Our whole economy is going to be dependent on how we respond to this crisis. Competition between countries will be between those who will be advanced in developing the technology and who will be selling it to others or those who stay back and don't seize the opportunity. We should never underestimate our ingenuity and resolve. If those people that say we cannot do anything about this do not know who we are, do not know what we can do.

I think this is the moment where we dig deep and say okay we are ready. The solutions are in front of us and no longer in good conscience can any of us, everyday citizens, elected officials, religious leaders, stand idly by. All the big problems that we have, they all have very local solutions and finding what those solutions are actually results in a whole bunch of different benefits from an environmental standpoint, economic standpoint and social aspect. We are in a situation where we're going to have an ecologically sustainable economy for everybody or ultimately we won't have one for anybody. It's just the smart thing to do to bet on the future and to being to invest in the future. The past has a lobby and it's a well-paid lobby and it comes right out of big oil and big coal. The future doesn't have a lobby until now. We have to be as sophisticated as the system we're trying to change. The legislation that Senator Boxer and I are introducing with the support of the leading environmental organizations actually addresses the crisis. A major focus is a price on carbon and methane emissions. I think a lot of people wondered, maybe still wonder, whether our political system is up to this task.

In the largest sense, I don't know if we can win this fight. There are scientists who think we've waited too long to get started. Clearly the power on the other side is enormous. Everyone once in awhile I get discouraged. There was TV reporter who was sort of grilling me who said, Well this just seems impossible. You're up against the richest industry on earth. This just seems like one of these David and Goliath stories. What chance do you have? And I was thinking, oh, you're right, this is terrible. But then I thought, and since we're in church, maybe this is apropos, you know, I thought, I know how that David and Goliath story comes out. David wins against the odds, okay. I don't know if we're going to win, but we have a real chance. We know that civil disobedience has helped to achieve great things. It's helped secure for women the right to vote. It's helped to end segregation.

And so we know that we can't win on climate change if we continue to dither, if we continue to talk about it but not do anything. We have a moral catastrophe on our hands. We have to do this because our democracy has been subverted, our laws have been subverted. I say it's criminal. I say that not lightly. When you have no recourse in our democracy, legally or democratically, we not only have the right but we have the duty to break the law to show our discontent. As a nation, we can come together. This is not about Republican or Democrat, it's about humanity. We're connected to each other and that organizing has got to be the basis for this kind of larger fight. We're very glad to be here, some of us are especially glad to be here because we're glad to be out of jail where we spent much of yesterday in this demonstration about the Keystone pipeline and that's, of course, of the reasons Americans are descending on this city this week. Thousands of people marched past the White House and urged President Obama to take strong measures to combat climate change.

In the second high profile event organized in a week by groups including the Sierra Club and 350.org. I'm here because I have an obligation to my children, my ancestors, our future generations. If this pipeline goes through, it will be at the cost of human life. When disaster strikes, it's not going to know race, color or creed. The fossil fuel barons, their lawyers, their spindoctors are losing their grip on our countries psyche. We're not going to create the clean energy economy when one side beats the other, we're going to win when we all come together for solutions that work for all of us. And the good news is that in this country, when we finally decided that we're going to take action on a moral question at the question of who we are we tend to respond, when we respond, explosively. That is the epic struggle of this century and we're going to meet it. If we don't we won't have a twenty-second century. Whenever a great generation stands up, it stands up based on idealism. It stands up based on moral courage and that's what's happening now.

This is the last minute of the last quarter of the biggest most important game humanity have ever played. The reality of our movement is this: if we fail, the consequences are dire. None of you could be in a more important place than you are right now. Part of this battle against the very deepest problems we've ever faced, very few people on earth ever get to say, "I'm doing the most important thing I can be doing any place on the planet at this moment in time" but you guys get to say that because you are on the front lines of this all-important battle. I think we can win this fight. I think we can win it if we act as a community, if we do not do anything that would injure that community but instead build and knit that community together in a way that allows it to take powerful action. We know the end of the story. Unless we rewrite the script, it's very clear how it ends with a planet that just heats out of control. So that's our job: to rewrite the story. All I ever wanted to see was a movement of people to stop climate change and now I've seen it. Today at the biggest climate rally by far, by far, by far in US history, today I know we're going to fight the battle, the most faithful battle in human history is finally joined and we will fight it together.

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Tim Jackson: An economic reality check

I want to talk to you today about prosperity, about our hopes for a shared and lasting prosperity. And not just us, but the two billion people worldwide who are still chronically undernourished. And hope actually is at the heart of this. In fact, the Latin word for hope is at the heart of the word prosperity. “Pro-speras,” “speras,” hope — in accordance with our hopes and expectations. The irony is, though, that we have cashed-out prosperity almost literally in terms of money and economic growth. And we’ve grown our economies so much that we now stand in a real danger of undermining hope — running down resources, cutting down rainforests, spilling oil into the Gulf of Mexico, changing the climate — and the only thing that has actually remotely slowed down the relentless rise of carbon emissions over the last two to three decades is recession.

And recession, of course, isn’t exactly a recipe for hope either, as we’re busy finding out. So we’re caught in a kind of trap. It’s a dilemma, a dilemma of growth. We can’t live with it; we can’t live without it. Trash the system or crash the planet — it’s a tough choice; it isn’t much of a choice. And our best avenue of escape from this actually is a kind of blind faith in our own cleverness and technology and efficiency and doing things more efficiently. Now I haven’t got anything against efficiency. And I think we are a clever species sometimes. But I think we should also just check the numbers, take a reality check here. So I want you to imagine a world, in 2050, of around nine billion people, all aspiring to Western incomes, Western lifestyles. And I want to ask the question — and we’ll give them that two percent hike in income, in salary each year as well, because we believe in growth. And I want to ask the question: how far and how fast would be have to move? How clever would we have to be? How much technology would we need in this world to deliver our carbon targets? And here in my chart — on the left-hand side is where we are now.

This is the carbon intensity of economic growth in the economy at the moment. It’s around about 770 grams of carbon. In the world I describe to you, we have to be right over here at the right-hand side at six grams of carbon. It’s a 130-fold improvement, and that is 10 times further and faster than anything we’ve ever achieved in industrial history. Maybe we can do it, maybe it’s possible — who knows? Maybe we can even go further and get an economy that pulls carbon out of the atmosphere, which is what we’re going to need to be doing by the end of the century. But shouldn’t we just check first that the economic system that we have is remotely capable of delivering this kind of improvement? So I want to just spend a couple of minutes on system dynamics.

It’s a bit complex, and I apologize for that. What I’ll try and do, is I’ll try and paraphrase it is sort of human terms. So it looks a little bit like this. Firms produce goods for households — that’s us — and provide us with incomes, and that’s even better, because we can spend those incomes on more goods and services. That’s called the circular flow of the economy. It looks harmless enough. I just want to highlight one key feature of this system, which is the role of investment. Now investment constitutes only about a fifth of the national income in most modern economies, but it plays an absolutely vital role. And what it does essentially is to stimulate further consumption growth. It does this in a couple of ways — chasing productivity, which drives down prices and encourages us to buy more stuff. But I want to concentrate on the role of investment in seeking out novelty, the production and consumption of novelty. Joseph Schumpeter called this “the process of creative destruction.” It’s a process of the production and reproduction of novelty, continually chasing expanding consumer markets, consumer goods, new consumer goods.

And this, this is where it gets interesting, because it turns out that human beings have something of an appetite for novelty. We love new stuff — new material stuff for sure — but also new ideas, new adventures, new experiences. But the materiality matters too, because in every society that anthropologists have looked at, material stuff operates as a kind of language — a language of goods, a symbolic language that we use to tell each other stories — stories, for example, about how important we are. Status-driven, conspicuous consumption thrives from the language of novelty. And here, all of a sudden, we have a system that is locking economic structure with social logic — the economic institutions, and who we are as people, locked together to drive an engine of growth.

And this engine is not just economic value; it is pulling material resources relentlessly through the system, driven by our own insatiable appetites, driven in fact by a sense of anxiety. Adam Smith, 200 years ago, spoke about our desire for a life without shame. A life without shame: in his day, what that meant was a linen shirt, and today, well, you still need the shirt, but you need the hybrid car, the HDTV, two holidays a year in the sun, the netbook and iPad, the list goes on — an almost inexhaustible supply of goods, driven by this anxiety. And even if we don’t want them, we need to buy them, because, if we don’t buy them, the system crashes. And to stop it crashing over the last two to three decades, we’ve expanded the money supply, expanded credit and debt, so that people can keep buying stuff. And of course, that expansion was deeply implicated in the crisis.

But this — I just want to show you some data here. This is what it looks like, essentially, this credit and debt system, just for the U.K. This was the last 15 years before the crash, and you can see there, consumer debt rose dramatically. It was above the GDP for three years in a row just before the crisis. And in the mean time, personal savings absolutely plummeted. The savings ratio, net savings, were below zero in the middle of 2008, just before the crash. This is people expanding debt, drawing down their savings, just to stay in the game. This is a strange, rather perverse, story, just to put it in very simple terms. It’s a story about us, people, being persuaded to spend money we don’t have on things we don’t need to create impressions that won’t last on people we don’t care about. (Laughter) (Applause) But before we consign ourselves to despair, maybe we should just go back and say, “Did we get this right? Is this really how people are? Is this really how economies behave?” And almost straightaway we actually run up against a couple of anomalies.

The first one is in the crisis itself. In the crisis, in the recession, what do people want to do? They want to hunker down, they want to look to the future. They want to spend less and save more. But saving is exactly the wrong thing to do from the system point of view. Keynes called this the “paradox of thrift” — saving slows down recovery. And politicians call on us continually to draw down more debt, to draw down our own savings even further, just so that we can get the show back on the road, so we can keep this growth-based economy going. It’s an anomaly, it’s a place where the system actually is at odds with who we are as people. Here’s another one — completely different one: Why is it that we don’t do the blindingly obvious things we should do to combat climate change, very, very simple things like buying energy-efficient appliances, putting in efficient lights, turning the lights off occasionally, insulating our homes? These things save carbon, they save energy, they save us money. So is it that, though they make perfect economic sense, we don’t do them? Well, I had my own personal insight into this a few years ago. It was a Sunday evening, Sunday afternoon, and it was just after — actually, to be honest, too long after — we had moved into a new house.

And I had finally got around to doing some draft stripping, installing insulation around the windows and doors to keep out the drafts. And my, then, five year-old daughter was helping me in the way that five year-olds do. And we’d been doing this for a while, when she turned to me very solemnly and said, “Will this really keep out the giraffes?” (Laughter) “Here they are, the giraffes.” You can hear the five-year-old mind working. These ones, interestingly, are 400 miles north of here outside Barrow-in-Furness in Cumbria. Goodness knows what they make of the Lake District weather. But actually that childish misrepresentation stuck with me, because it suddenly became clear to me why we don’t do the blindingly obvious things. We’re too busy keeping out the giraffes — putting the kids on the bus in the morning, getting ourselves to work on time, surviving email overload and shop floor politics, foraging for groceries, throwing together meals, escaping for a couple of precious hours in the evening into prime-time TV or TED online, getting from one end of the day to the other, keeping out the giraffes.

(Laughter) What is the objective? “What is the objective of the consumer?” Mary Douglas asked in an essay on poverty written 35 years ago. “It is,” she said, “to help create the social world and find a credible place in it.” That is a deeply humanizing vision of our lives, and it’s a completely different vision than the one that lies at the heart of this economic model. So who are we? Who are these people? Are we these novelty-seeking, hedonistic, selfish individuals? Or might we actually occasionally be something like the selfless altruist depicted in Rembrandt’s lovely, lovely sketch here? Well psychology actually says there is a tension — a tension between self-regarding behaviors and other regarding behaviors. And these tensions have deep evolutionary roots, so selfish behavior is adaptive in certain circumstances — fight or flight. But other regarding behaviors are essential to our evolution as social beings.

And perhaps even more interesting from our point of view, another tension between novelty-seeking behaviors and tradition or conservation. Novelty is adaptive when things are changing and you need to adapt yourself. Tradition is essential to lay down the stability to raise families and form cohesive social groups. So here, all of a sudden, we’re looking at a map of the human heart. And it reveals to us, suddenly, the crux of the matter. What we’ve done is we’ve created economies. We’ve created systems, which systematically privilege, encourage, one narrow quadrant of the human soul and left the others unregarded. And in the same token, the solution becomes clear, because this isn’t, therefore, about changing human nature. It isn’t, in fact, about curtailing possibilities. It is about opening up. It is about allowing ourselves the freedom to become fully human, recognizing the depth and the breadth of the human psyche and building institutions to protect Rembrandt’s fragile altruist within.

What does all this mean for economics? What would economies look like if we took that vision of human nature at their heart and stretched them along these orthogonal dimensions of the human psyche? Well, it might look a little bit like the 4,000 community-interest companies that have sprung up in the U.K. over the last five years and a similar rise in B corporations in the United States, enterprises that have ecological and social goals written into their constitution at their heart — companies, in fact, like this one, Ecosia. And I just want to, very quickly, show you this. Ecosia is an Internet search engine. Internet search engines work by drawing revenues from sponsored links that appear when you do a search. And Ecosia works in pretty much the same way. So we can do that here — we can just put in a little search term. There you go, Oxford, that’s where we are. See what comes up.

The difference with Ecosia though is that, in Ecosia’s case, it draws the revenues in the same way, but it allocates 80 percent of those revenues to a rainforest protection project in the Amazon. And we’re going to do it. We’re just going to click on Naturejobs.uk. In case anyone out there is looking for a job in a recession, that’s the page to go to. And what happened then was the sponsor gave revenues to Ecosia, and Ecosia is giving 80 percent of those revenues to a rainforest protection project. It’s taking profits from one place and allocating them into the protection of ecological resources. It’s a different kind of enterprise for a new economy. It’s a form, if you like, of ecological altruism — perhaps something along those lines. Maybe it’s that. Whatever it is, whatever this new economy is, what we need the economy to do, in fact, is to put investment back into the heart of the model, to re-conceive investment. Only now, investment isn’t going to be about the relentless and mindless pursuit of consumption growth.

Investment has to be a different beast. Investment has to be, in the new economy, protecting and nurturing the ecological assets on which our future depends. It has to be about transition. It has to be investing in low-carbon technologies and infrastructures. We have to invest, in fact, in the idea of a meaningful prosperity, providing capabilities for people to flourish. And of course, this task has material dimensions. It would be nonsense to talk about people flourishing if they didn’t have food, clothing and shelter. But it’s also clear that prosperity goes beyond this. It has social and psychological aims — family, friendship, commitments, society, participating in the life of that society. And this too requires investment, investment — for example, in places — places where we can connect, places where we can participate, shared spaces, concert halls, gardens, public parks, libraries, museums, quiet centers, places of joy and celebration, places of tranquility and contemplation, sites for the “cultivation of a common citizenship,” in Michael Sandel’s lovely phrase.

An investment — investment, after all, is just such a basic economic concept — is nothing more nor less than a relationship between the present and the future, a shared present and a common future. And we need that relationship to reflect, to reclaim hope. So let me come back, with this sense of hope, to the two billion people still trying to live each day on less than the price of a skinny latte from the cafe next door. What can we offer those people? It’s clear that we have a responsibility to help lift them out of poverty. It’s clear that we have a responsibility to make room for growth where growth really matters in those poorest nations. And it’s also clear that we will never achieve that unless we’re capable of redefining a meaningful sense of prosperity in the richer nations, a prosperity that is more meaningful and less materialistic than the growth-based model.

So this is not just a Western post-materialist fantasy. In fact, an African philosopher wrote to me, when “Prosperity Without Growth” was published, pointing out the similarities between this view of prosperity and the traditional African concept of ubuntu. Ubuntu says, “I am because we are.” Prosperity is a shared endeavor. Its roots are long and deep — its foundations, I’ve tried to show, exist already, inside each of us. So this is not about standing in the way of development. It’s not about overthrowing capitalism. It’s not about trying to change human nature. What we’re doing here is we’re taking a few simple steps towards an economics fit for purpose. And at the heart of that economics, we’re placing a more credible, more robust, and more realistic vision of what it means to be human. Thank you very much.

(Applause) Chris Anderson: While they’re taking the podium away, just a quick question. First of all, economists aren’t supposed to be inspiring, so you may need to work on the tone a little. (Laughter) Can you picture the politicians ever buying into this? I mean, can you picture a politician standing up in Britain and saying, “GDP fell two percent this year. Good news! We’re actually all happier, and a country’s more beautiful, and our lives are better.” Tim Jackson: Well that’s clearly not what you’re doing. You’re not making news out of things falling down. You’re making news out of the things that tell you that we’re flourishing. Can I picture politicians doing it? Actually, I already am seeing a little bit of it. When we first started this kind of work, politicians would stand up, treasury spokesmen would stand up, and accuse us of wanting to go back and live in caves. And actually in the period through which we’ve been working over the last 18 years — partly because of the financial crisis and a little bit of humility in the profession of economics — actually people are engaging in this issue in all sorts of countries around the world. CA: But is it mainly politicians who are going to have to get their act together, or is it going to be more just civil society and companies? TJ: It has to be companies.

It has to be civil society. But it has to have political leadership. This is a kind of agenda, which actually politicians themselves are kind of caught in that dilemma, because they’re hooked on the growth model themselves. But actually opening up the space to think about different ways of governing, different kinds of politics, and creating the space for civil society and businesses to operate differently — absolutely vital. CA: And if someone could convince you that we actually can make the — what was it? — the 130-fold improvement in efficiency, of reduction of carbon footprint, would you then actually like that picture of economic growth into more knowledge-based goods? TJ: I would still want to know that you could do that and get below zero by the end of the century, in terms of taking carbon out of the atmosphere, and solve the problem of biodiversity and reduce the impact on land use and do something about the erosion of topsoils and the quality of water. If you can convince me we can do all that, then, yes, I would take the two percent.

CA: Tim, thank you for a very important talk. Thank you. (Applause).

The Greatest Threat to Existence as We Know it

imagine its a beautiful day in April of 2017 three children in different parts of the world are going about their daily lives as they do every day and as their parents have done for countless generations meet Hiro in Japan Hiro wants to be a successful banker one day just like his father but right now he is more interested in spaceships and planets Abasie lives in Kenya with his parents and grandparents one day he wants to travel the world in his own little sailboat akash lives in india with his big happy family when Akash grows up he wants to be the world's greatest chef and so life goes on hiro becomes an astronaut much to his fathers suprise Abasie travels the world in his sailboat and Akash opened his own restaurant in his home town they grow old and pass on having lived fulfilled lifes their children follow and thier children's children until one day in April of 2100 Akoh and his family are crammed with thousands of other people at Haneda Airport hoping it's not too late sadly the people of Tokyo never had a chance the once-proud city is reduced to rubble by tsunami the likes of which has never been seen Anassa lyes in the dark of his quiet home and he knows his time has come it hasn't rained in months all the crops and livestock have died and the well dried up long ago the people of Kenya suffer the slow death of starvation and dehydration oni draws ragged breaths in his hospital bed his body ravaged by disease is the last living member of his family the population of India has fallen drastically these are a few hypothetical scenarios from various parts of the globe while they may seem unrelated they all share a common catalyst climate change as 2017 begins and the United States presidency changes hands it has become increasingly apparent that the new regime is full of climate change deniers and fossil fuel advocates it is more important than ever to spread real information regarding climate change and the catastrophic effects it can produce within the next 100 years let's start with the common misconception when some people hear the term global warming they'll point to an instance of colder than normal weather like the Sahara Desert recently and say that's ridiculous it's snowing here this objection stems from a misunderstanding of how weather differs from climate weather refers to local changes over short periods of time such as minutes hours days or weeks typical examples of whether include rain clouds snow wind and thunderstorms climate refers to longer-term averages and maybe regional or global in scale and can be thought of as weather averaged over an extended period of time typically years or decades an easy way to remember the distinction is weather is what you get climate is what you expect now that we have a good understanding of how climate and weather differ let's look at the scientific consensus over ninety seven percent of actively publishing climate scientists agree that climate warming trends over the past 100 years are extremely likely to have been caused largely by human activity that number goes up to over ninety-nine percent if you include climate scientists who have not recently published scholarly articles most of the leading scientific organizations around the world have issued public statements endorsing this position there are too many to list in this video so i put a link in the description of organizations and their statements climate change deniers tend to latch onto studies that disprove the trend but you always notice that the studies are either not peer-reviewed come from a known anti-science publisher or come from a scientist in a completely unrelated filled with an agenda of their own so where does this problem come from the largest contributing factor to climate change is the burning of fossil fuels oil coal and natural gas all release carbon dioxide into the atmosphere when burned carbon dioxide is considered a greenhouse gas which simply means it sticks around in the upper atmosphere and traps heat the more carbon dioxide is released the more the atmosphere heats up this temperature increase then causes other problems such as melting glaciers and polar ice as arctic ice melts it releases co2 and methane a more potent greenhouse gas compounding the problem by making the atmosphere even warmer the smelting morais it's a vicious cycle ok but where do we stand right now what's the damage as of the end of 2016 carbon dioxide levels are up by nearly 405 parts-per-million the highest in 650,000 years global temperatures up by one point seven degrees since eighteen eighty and nine of the last ten hottest years on record happened since 2000 the tenth being 1998 Arctic ice is shrinking at a rate of 13.

3 percent per decade and land ice is disappearing at a rate of 281 gigatons per year Greenland ice loss doubled between 1996 in 2005 and finally the global sea level has risen seven inches in the last 100 you're probably thinking well that doesn't sound too bad let's look at the consequences by category first the melting of polar ice of course we've all heard that global warming affects the poor polar bears but it's true and it's severe at the current rate of melting which is likely to increase the Arctic is projected to see its first ice-free summer by 2050 imagine that all of the ice gone and yes that likely means extinction for the polar bears within a hundred years and it's not just polar bears some species of ice dependent seals will die off if they can't adapt including harp ringed ribbon and bearded seals then there are the ivory goals and ox ivory goals have already suffered a ninety percent population reduction in Canada over the past 20 years then there's the walrus the arctic fox small plant eaters like ground squirrels hairs lemmings involves large planters like moose caribou reindeer and musk ox and meat eaters like weasels wolverines wolves foxes bears and birds of prey the melting ice is likely to cause a domino effect knocking out species that other species depend upon for food melting ice brings us to our next category rising sea level over the past 100 years the global sea level has risen approximately seven inches the more alarming fact is that the rate of rise in the last decade is nearly double the rate of the entire last century at this rate rising sea level puts coastal cities and islands at great risk SC water reaches further inland it can cause destructive erosion flooding of wetlands contamination of aquifers and agricultural soils and lost habitat for fish birds and plants most projections show the sea level will rise between point 8 and 2 meters by 2100 which would be catastrophic for many low-lying islands and much of the eastern coast of the United States more dire predictions based upon the complete melting of the Greenland ice sheet project a rise up to seven meters that's enough to submerge London the third category is the one with which most people are familiar global temperature rise as CO2 accumulates in our atmosphere the temperature creeps steadily upward the annual increase is measured at roughly 1.

7 degrees Fahrenheit this increase in temperature could cause the most drastic immediate effects of all three categories the list is long and distressing so here we go global warming will cause droughts and heat waves which are already responsible for killing more people per year than floods hurricanes lightning and tornadoes combined it will aggravate the spread of disease warmer weather allows disease bears to be active longer and further abroad warmer ocean temperatures will allow pathogens to flourish as we've already seen with the widespread coral bleaching of the Great Barrier Reef this coral houses twenty-five percent of all marine diversity and the reef is already declined by fifty percent in the last thirty years when the coral goes we'll lose hundreds of thousands of species dependent upon it for shelter which will collapse much of the marine food chain back on land fishing will suffer droughts will destroy crops and livestock and create a water scarcity pushing farmers and people in rural areas into the city this will cause overcrowding and help spark civil wars that killed hundreds of thousands like it did in Syria GDP is expected to plummet by twenty-three percent by 2100 caused by property damage from flooding droughts wildfires storms loss of productivity loss of tourism and illness you can see how quickly the situation can snowball wildly out-of-control it seems very dire but what can we do is it too late to stop the changes we put in motion it's hard to say for sure but the affect humans have had on this earth is severe and the changes have indeed been set in motion even if we stopped emitting greenhouse gases today global warming would continue for at least several more decades since carbon dioxide can linger in the atmosphere for up to centuries some experts believe we're approaching a tipping point a point at which abrupt perhaps irreversible changes would tip our climate into a new state however it may not be too late to limit some of the worst effects of climate change two important steps are required one mitigation the reduction of greenhouse gas emissions into the atmosphere and two adaptation learning to cope with and adapt to the climate changes that have already been set in motion recycling and driving fuel-efficient cars are important steps in the right direction but not sufficient on their own it will take a globally coordinated response such as clean energy agreements between nations as well as local efforts on the city and regional level such as sustainable City Planning public transportation upgrades and energy efficiency improvements so yes climate change is the biggest threat to existence as we know it and is deeply troubling that the United States government seeks to normalize ignorance of good science so if you're concerned for the future of the planet and generations to come do your part help spread this information because the earth truly is worth saving if you enjoyed this video please leave a like or a comment and subscribe to keep up with the latest content thanks for watching and we'll see you in the next video.