Strong global warming since mids is reported, with the warmest year on record. Speculation over catastrophic climate change following a nuclear war, or a dinosaur-killing asteroid strike, promote realization of the atmosphere's fragility. Villach Conference declares consensus among experts that some global warming seems inevitable, calls on governments to consider international agreements to restrict emissions.
Antarctic ice cores show that CO 2 and temperature went up and down together through past ice ages, pointing to powerful feedbacks. Broecker speculates that a reorganization of North Atlantic Ocean circulation can bring swift and radical climate change.
Toronto conference calls for strict, specific limits on greenhouse gas emissions; UK Prime Minister Thatcher is first major leader to call for action. Ice-core and biology studies confirm living ecosystems give climate feedback by way of methane, which could accelerate global warming.
Pinatubo explodes; Hansen predicts cooling pattern, verifying by computer models of aerosol effects. Global warming skeptics claim that 20th-century temperature changes followed from solar influences. The solar-climate correlation would fail in the following decade. Geologists discover massive extinction event 55 million years ago, associated with tremendous warming caused by increase in greenhouse gases. Study of ancient climates reveals climate sensitivity to CO 2 in same range as predicted independently by computer models.
Reports of the breaking up of Antarctic ice shelves and other signs of actual current warming in polar regions begin affecting public opinion.
International conference produces Kyoto Protocol, setting targets for industrialized nations to reduce greenhouse gas emissions if enough nations sign onto a treaty rejected by U. Senate in advance. Borehole data confirm extraordinary warming trend. Qualms about arbitrariness in computer models diminish as teams model ice-age climate and dispense with special adjustments to reproduce current climate.
Mann's "hockey stick" data indicates current warming is historically unprecedented. Ramanathan detects massive "brown cloud" of aerosols over South Asia. Variety of studies emphasize variability and importance of biological feedbacks in carbon cycle, liable to accelerate warming. Effective end of debate among all but a few scientists. Bonn meeting, with participation of most countries but not US, develops mechanisms for working towards Kyoto targets.
National Academy of Sciences panel sees a "paradigm shift" in scientific recognition of the risk of abrupt decade-scale climate change. The number of days that a baby spends in the womb over 90 degrees can be seen on its lifetime earnings. That's how dramatic the effect of temperature on child development is.
It's about the saiga antelope, which is this dwarf antelope that lived in Siberia, and a few years ago — I think it was in — the entire species got wiped out because a bacteria that had lived inside their guts for millions of years was rewired by a summer that was especially hot and humid, and what had been a quite happy cohabitant of that saiga digestive tract became an enemy of the animal and killed the entire species.
Biology is as well. We have millions and perhaps billions of bacteria living inside us and viruses living inside us. And while it's probably the case that the overwhelming majority of those won't be affected by temperature rises of just 2 or 3 or 4 degrees, the chance that one of them or several of them is transformed in that way is quite serious.
And that doesn't mean that humans are going to be made extinct. But there's a relationship between schizophrenia and viruses that you've been exposed to.
There's a relationship between mood disorders. There's a relationship with obesity. So many aspects of the way that we think of our relationship to the world are determined in part by these other creatures that are living inside us and every single one of them is subject to the transformations that will be brought about by climate change. On what needs to happen to avert a worst-case scenario. I think it's unlikely that we'd do that. But that's not a reason for slowing down now. It's not a matter of whether we reach a hellish climate scenario or not.
Every tick upward of temperature produces more suffering, more pain, and every tick that we can avoid will make the world a better place in the future. So while I think it's unrealistic that we entirely zero out on carbon by , I think we should marshal as many resources as we possibly can to achieve that goal.
The story of climate change is so big that we can't solve it through small actions. We need a big policy response. On humanity having to adjust to the new living conditions climate change could create, regardless of what kind of action is taken. Which is to say, even if we take quite dramatic action and really transform our trajectory on climate change — which is possible, everything is within our control, everything is up to us.
It's not outside of our power. But even if we do that, we will be left with a world that is dramatically shaped by climate change, because it will mean huge new plantations of solar panel plants. It will mean plantations of carbon-capture technology which suck carbon out of the atmosphere.
It will mean an entirely new infrastructure. It will mean new kinds of airplanes, new kinds of public transportation. It will mean a new approach to diet and agriculture. Now thankfully, there's still time to imagine a world that is made prosperous and fulfilling and just through climate action.
On trying to get the message across to politicians in the U. I've heard from a lot of political leaders on the other side of the aisle who are actually making quite enormous progress in this area. When I started working on climate a few years ago, it was conventional wisdom, which I'd sort of took for granted, that the public and our politics was quite inert on the subject, that it just wasn't moving at all and there wasn't much chance for rapid movement.
Those are incredibly rapid movements by any political science standard, although they're a little too slow given how fast we need to take action to really avert some catastrophic change. On the emotional burden of caring about climate change.
It imposes an emotional cost on all of us to think about the world's suffering in all these ways. Thankfully though, I think it's all in front of us: If we get to some of these truly terrifying outcomes, it will be because of the choices we make from here on out. In fact, all but the one that killed the dinosaurs were caused by climate change produced by greenhouse gas. The most notorious was million years ago; it began when carbon warmed the planet by five degrees, accelerated when that warming triggered the release of methane in the Arctic, and ended with 97 percent of all life on Earth dead.
We are currently adding carbon to the atmosphere at a considerably faster rate; by most estimates, at least ten times faster. The rate is accelerating. This is what Stephen Hawking had in mind when he said , this spring, that the species needs to colonize other planets in the next century to survive, and what drove Elon Musk, last month, to unveil his plans to build a Mars habitat in 40 to years.
These are nonspecialists, of course, and probably as inclined to irrational panic as you or I. But the many sober-minded scientists I interviewed over the past several months — the most credentialed and tenured in the field, few of them inclined to alarmism and many advisers to the IPCC who nevertheless criticize its conservatism — have quietly reached an apocalyptic conclusion, too: No plausible program of emissions reductions alone can prevent climate disaster.
And however sanguine you might be about the proposition that we have already ravaged the natural world, which we surely have, it is another thing entirely to consider the possibility that we have only provoked it, engineering first in ignorance and then in denial a climate system that will now go to war with us for many centuries, perhaps until it destroys us. The bahraining of New York. Humans, like all mammals, are heat engines; surviving means having to continually cool off, like panting dogs.
For that, the temperature needs to be low enough for the air to act as a kind of refrigerant, drawing heat off the skin so the engine can keep pumping. And the effect would be fast: Within a few hours, a human body would be cooked to death from both inside and out. Climate-change skeptics point out that the planet has warmed and cooled many times before, but the climate window that has allowed for human life is very narrow, even by the standards of planetary history.
This century, and especially in the tropics, the pain points will pinch much more quickly even than an increase of seven degrees. At present, most regions reach a wet-bulb maximum of 26 or 27 degrees Celsius; the true red line for habitability is 35 degrees. What is called heat stress comes much sooner. Since , the planet has experienced a fold increase in the number of places experiencing dangerous or extreme heat; a bigger increase is to come.
The five warmest summers in Europe since have all occurred since , and soon, the IPCC warns, simply being outdoors that time of year will be unhealthy for much of the globe.
Even if we meet the Paris goals of two degrees warming, cities like Karachi and Kolkata will become close to uninhabitable, annually encountering deadly heat waves like those that crippled them in At four degrees, the deadly European heat wave of , which killed as many as 2, people a day, will be a normal summer.
At six, according to an assessment focused only on effects within the U. By the end of the century, the World Bank has estimated, the coolest months in tropical South America, Africa, and the Pacific are likely to be warmer than the warmest months at the end of the 20th century.
Air-conditioning can help but will ultimately only add to the carbon problem; plus, the climate-controlled malls of the Arab emirates aside, it is not remotely plausible to wholesale air-condition all the hottest parts of the world, many of them also the poorest. And indeed, the crisis will be most dramatic across the Middle East and Persian Gulf, where in the heat index registered temperatures as high as degrees Fahrenheit.
As soon as several decades from now, the hajj will become physically impossible for the 2 million Muslims who make the pilgrimage each year. It is not just the hajj, and it is not just Mecca; heat is already killing us. In the sugarcane region of El Salvador, as much as one-fifth of the population has chronic kidney disease, including over a quarter of the men, the presumed result of dehydration from working the fields they were able to comfortably harvest as recently as two decades ago.
With dialysis, which is expensive, those with kidney failure can expect to live five years; without it, life expectancy is in the weeks. Of course, heat stress promises to pummel us in places other than our kidneys, too. As I type that sentence, in the California desert in mid-June, it is degrees outside my door. It is not a record high. Praying for cornfields in the tundra.
Climates differ and plants vary, but the basic rule for staple cereal crops grown at optimal temperature is that for every degree of warming, yields decline by 10 percent.
Some estimates run as high as 15 or even 17 percent. Which means that if the planet is five degrees warmer at the end of the century, we may have as many as 50 percent more people to feed and 50 percent less grain to give them. And proteins are worse: It takes 16 calories of grain to produce just a single calorie of hamburger meat, butchered from a cow that spent its life polluting the climate with methane farts.
Pollyannaish plant physiologists will point out that the cereal-crop math applies only to those regions already at peak growing temperature, and they are right — theoretically, a warmer climate will make it easier to grow corn in Greenland. But as the pathbreaking work by Rosamond Naylor and David Battisti has shown, the tropics are already too hot to efficiently grow grain, and those places where grain is produced today are already at optimal growing temperature — which means even a small warming will push them down the slope of declining productivity.
Precipitation is notoriously hard to model, yet predictions for later this century are basically unanimous: unprecedented droughts nearly everywhere food is today produced. By , without dramatic reductions in emissions, southern Europe will be in permanent extreme drought, much worse than the American dust bowl ever was. The same will be true in Iraq and Syria and much of the rest of the Middle East; some of the most densely populated parts of Australia, Africa, and South America; and the breadbasket regions of China.
Remember, we do not live in a world without hunger as it is. Far from it: Most estimates put the number of undernourished at million globally. What happens when the bubonic ice melts? Rock, in the right spot, is a record of planetary history, eras as long as millions of years flattened by the forces of geological time into strata with amplitudes of just inches, or just an inch, or even less.
Ice works that way, too, as a climate ledger, but it is also frozen history, some of which can be reanimated when unfrozen. There are now, trapped in Arctic ice, diseases that have not circulated in the air for millions of years — in some cases, since before humans were around to encounter them. Which means our immune systems would have no idea how to fight back when those prehistoric plagues emerge from the ice. The Arctic also stores terrifying bugs from more recent times.
As the BBC reported in May, scientists suspect smallpox and the bubonic plague are trapped in Siberian ice, too — an abridged history of devastating human sickness, left out like egg salad in the Arctic sun. But already last year, a boy was killed and 20 others infected by anthrax released when retreating permafrost exposed the frozen carcass of a reindeer killed by the bacteria at least 75 years earlier; 2, present-day reindeer were infected, too, carrying and spreading the disease beyond the tundra.
What concerns epidemiologists more than ancient diseases are existing scourges relocated, rewired, or even re-evolved by warming. The first effect is geographical. Before the early-modern period, when adventuring sailboats accelerated the mixing of peoples and their bugs, human provinciality was a guard against pandemic.
But as the tropics creep northward and mosquitoes migrate with them, you will. As it happens, Zika may also be a good model of the second worrying effect — disease mutation. But there are things we do know for sure about how climate affects some diseases: Malaria, for instance, thrives in hotter regions not just because the mosquitoes that carry it do, too, but because for every degree increase in temperature, the parasite reproduces ten times faster.
Which is one reason that the World Bank estimates that by , 5. A rolling death smog that suffocates millions. Our lungs need oxygen, but that is only a fraction of what we breathe.
The fraction of carbon dioxide is growing: It just crossed parts per million, and high-end estimates extrapolating from current trends suggest it will hit 1, ppm by At that concentration, compared to the air we breathe now, human cognitive ability declines by 21 percent.
Other stuff in the hotter air is even scarier, with small increases in pollution capable of shortening life spans by ten years.
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