Indeed, meteorological theory holds that, outside the tropics, weather in a warming world should be less variable, which might be a good thing. In many other respects, the ill effects of warming are overblown. Sea levels, for example, have been increasing since the end of the last ice age. When you look at recent centuries in perspective, ignoring short-term fluctuations, the rate of sea-level rise has been relatively uniform less than a couple of millimeters a year.
There's even some evidence that the rate was higher in the first half of the twentieth century than in the second half. Overall, the risk of sea-level rise from global warming is less at almost any given location than that from other causes, such as tectonic motions of the earth's surface. Many of the most alarming studies rely on long-range predictions using inherently untrustworthy climate models, similar to those that cannot accurately forecast the weather a week from now.
Interpretations of these studies rarely consider that the impact of carbon on temperature goes down—not up—the more carbon accumulates in the atmosphere. Even if emissions were the sole cause of the recent temperature rise—a dubious proposition—future increases wouldn't be as steep as the climb in emissions. Indeed, one overlooked mystery is why temperatures are not already higher.
Various models predict that a doubling of CO2 in the atmosphere will raise the world's average temperature by as little as 1.
The important thing about doubled CO2 or any other greenhouse gas is its "forcing"—its contribution to warming. And that decline occurred over a period when the global population quadrupled. What about sea level rise? IPCC estimates sea level could rise two feet 0. Consider that one-third of the Netherlands is below sea level, and some areas are seven meters below sea level. You might object that Netherlands is rich while Bangladesh is poor. But the Netherlands adapted to living below sea level years ago.
Technology has improved a bit since then. What about claims of crop failure, famine, and mass death? It could. But such declines should be put in perspective. Rates of future yield growth depend far more on whether poor nations get access to tractors, irrigation, and fertilizer than on climate change, says FAO. All of this helps explain why IPCC anticipates climate change will have a modest impact on economic growth. One of the reasons I work on climate change is because I worry about the impact it could have on endangered species.
Climate change may threaten one million species globally and half of all mammals, reptiles, and amphibians in diverse places like the Albertine Rift in central Africa, home to the endangered mountain gorilla. As tragic as animal extinctions are, they do not threaten human civilization. If we want to save endangered species, we need to do so because we care about wildlife for spiritual, ethical, or aesthetic reasons, not survival ones.
And exaggerating the risk, and suggesting climate change is more important than things like habitat destruction, are counterproductive. Should we worry about koalas? We serve on a committee for NASA together, but it only deals with specific satellite issues. At the Ways and Means hearing, he was sitting two people down from me, but he did not want to engage any of the evidence I presented. And that seems to be the preferred tactic of many in the alarmist camp. Rather than bring up these issues, they simply ignore them.
Contacted by Fortune, Hansen acknowledges that his projections were based on a model that "slightly" overstated the warming created by a doubling in CO2 levels. His new model posits a rise of 3 degrees Celsius in global temperatures by , vs. Says Hansen, "The projections that the public has been hearing about are based on a climate sensitivity that is consistent with the global warming rate of the past few decades.
I know you think there's been something of a hysteria in the media about melting glaciers. Could you explain? Ice melts. Glaciers are always calving.
This is what ice does. If ice did not melt, we'd have an ice-covered planet. The fact is that the ice cover is growing in the southern hemisphere even as the ice cover is more or less shrinking in the northern hemisphere. As you and I are talking today, global sea ice coverage is about , square kilometers above the long-term average - which means that the surplus in the Antarctic is greater than the deficit in the Arctic.
What about the better-safe-than-sorry argument? Even if there's a chance Gore and Hansen are wrong, shouldn't we still take action in order to protect ourselves from catastrophe, just in case they're right? The problem is that the solutions being offered don't provide any detectable relief from this so-called catastrophe. That's basically the equivalent of building 1, new nuclear power plants all operating by Now I'm all in favor of nuclear energy, but that would affect the global temperature by only seven-hundredths of a degree by and fifteen hundredths by We wouldn't even notice it.
See all CNNMoney. John Christy says that global warming has been overestimated. Date April 22, February 9, Here are their answers. This question presupposes that I am scared about climate change. How dare you ask such a question to a career sustainability professional? Being scared is being afraid, terrified, and at worst, emotional to the point of being catatonic. I demand, no, I respectfully deserve a better question, a positive, uplifting question, especially on the 50th anniversary of Earth Day ….
My Rachel Carson moment of being present to the enormity of the challenges that come with global climate disruption happened when I was a doctoral student at Tufts just starting my background literature search. It was , and Nature just published a journal article by [James E. When disruption occurs, it comes with accelerating forces due to failures of climate regulation, unleashing reinforcing feedbacks that further amplify increases in global temperatures.
My fear is, despite the science and the early warning signals that we bear witness to — record temperatures, 1,year storms, glacial retreat, coral reefs dying on a continental scale — global society may finally wake up, but it may be too late. Our current global political economy solves problems through business as usual growth, wasting precious time to effectively reduce emissions to prevent human suffering and ecological system collapse at an unimaginable scale.
I may not live long enough to experience the severe effects of climate change. However, when I look around the Harvard community, a truly global community, I see a growing younger generation of people who will experience severe impacts.
They get it. They know. With courage, leadership, and a moral compass to make the world a better place, together, the Harvard community has the ability to make a difference on a global scale that will inspire others to also make a positive difference. And this gives me hope. To combat fear that grows from inaction and inadequate leadership, we must remind ourselves time and again that we have solutions to the climate crisis and that these solutions improve health today, especially for the poor and vulnerable, and that they provide for a more just and livable world for our children.
While much, much more needs to be done to put us on the right path to avert the worst effects of climate change, the growth of renewable energy around the world, the rise of electric vehicles, and the growing appreciation for plant-based diets all give reason for hope over fear. For anyone who doubts our individual actions matter, look no further than what is happening in communities across this country right now. By keeping our distance from others, we have saved tens of thousands of lives, especially among the poor, older people, and those whose health is compromised.
With COVID, of course, we have been asked and in some cases commanded to change our ways by our leaders. Our individual climate actions can have the same effect. As individuals act, we can create a path that many more will walk on.
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