Climate 'Weirdness' Throws Ecosystems 'Out Of Kilter'
Science journalist Michael Lemonick doesn't want to be a doomsday prophet, but he does want to be realistic about the threat of climate change. "Since I started writing about climate change all the way back in 1987, we've known what the cause is, we've known what the likely outcome is, and we've had time to act — and essentially we haven't acted," he tells Fresh Air's Dave Davies.
Lemonick is the co-author of a new book, Global Weirdness: Severe Storms, Deadly Heat Waves, Relentless Drought, Rising Seas, and the Weather of the Future. The book, published by the nonprofit research organization Climate Central, details the effects of climate change and greenhouse gases in ocean acidity, existing ecosystems, disruptions to food supply and rising sea levels. Lemonick says sea level has risen by about eight inches overall worldwide since around 1900, and the waters are expected to rise an estimated three feet by 2100.
"Sometimes we forget that the damage in New Orleans in 2005 from Hurricane Katrina came not from wind or rain, but from the storm surge [that caused flooding] ahead of that storm," Lemonick says. If sea levels rise as expected, "all of those storm surges are going to be starting from a level three feet higher, which means that they have much greater potential to drive inland, to wash over barrier islands, and to really inundate the coast. ... Many, many millions of people and trillions of dollars of infrastructure are in serious danger, if those projections are correct."
On how scientists calculate temperatures from hundreds of thousands of years ago
"One very important way we know about the temperature in the past is that if you go to Greenland or to Antarctica and drill deep into the ice, what you find is air bubbles trapped as snow fell thousands of years ago [and] hundreds of thousands of years ago. Air was trapped in among the snowflakes, and when it was compressed into ice — those air bubbles ... are actually time capsules that show you exactly what the atmosphere was like at any time up to 800,000 years ago. ...
"What we can look at directly is the amount of carbon dioxide that was in the air, and that has gone up and down. You can also deduce what the temperature was by the chemical characteristics of the snow itself: The ice that was once snow, depending on what the temperature was, the different chemical composition of the ice will say [whether] it was warmer or colder."
On carbon dioxide making the oceans more acidic
"While it's true that the primary effect of carbon dioxide buildup is to warm the Earth and to change the climate, some of that carbon dioxide is absorbed by the oceans, and when water absorbs carbon dioxide, it becomes more acidic. ... That has some implications for sea life, especially organisms that form shells: In an acidic environment it's harder to form a shell, and because a lot of these organisms are at the very base of the ocean food chain, there could be some real disruptions to that part of our food supply. "
On how long carbon dioxide stays in the atmosphere
"Carbon dioxide is naturally removed from the atmosphere by all sorts of natural processes and always has been, and that's why it's always been in balance for the last ... 10,000 years or so. We've started adding carbon dioxide, but we haven't added any new mechanisms to remove it. So it has been building up, and the natural forces that remove it from the atmosphere are going at their own normal steady pace, the result being that the carbon dioxide we've put into the atmosphere so far is mostly still up there, and it will stay up there for a long, long time. In fact, it will be up there warming the Earth for many, many hundreds of years to come. The bad news is that if we were to cut back on emissions drastically today, which we're not doing, we've already built more warming into the system, and a sort of continuous warming that will go on for a long, long time."
On the effect climate change will have on infectious diseases
"Many infectious diseases are carried by vectors — animals, insects, mosquitoes, flies and so on, and those animals live at a certain range — they thrive in a certain range of conditions. As the climate changes, their comfortable habitat is also likely to change, and it's likely that at least some of these [animals and insects] will invade areas where they were formally rare.
"This is one of these instances where you have to be careful about not ascribing everything to climate change. Climate change will have an effect on the distribution of disease-carrying mosquitoes, for example, but it's also important to realize that malaria, which we think of as a tropical disease, was actually endemic in large parts of the U.S., including Philadelphia and including New Jersey, up until about 1900, and widespread swamp drainage and mosquito eradication programs have helped to eliminate it. So the public health infrastructure in any given place is a big factor in whether these disease outbreaks will actually be severe or not. Climate change will just be one more factor pushing toward more disease outbreaks; it's not the only one."
The effect of climate change on animal populations
"We are seeing effects on animal populations in subtle ways, but they're getting less subtle. One thing that's kind of striking: ... The whole ecosystem is going to have to move north as the climate gets warmer to look for comfortable temperatures. But what biologists are seeing is that an ecosystem is composed of many, many species, and those species react differently to climate change. Some are more resilient, some are less resilient, and there have been a number of studies ... that show that migrating birds are being affected in a kind of a surprising way, which is to say they migrate partly to keep time with the changes in species, the flowering of plants or the emergence of butterflies in the place that they migrate to.
"There was a study a couple years ago, I believe ... where birds were arriving [in Europe] from Africa, ready to feast on the larvae of certain butterflies, but the larvae had already come out two weeks earlier, and they'd all flown away, and there was nothing for the birds to eat. So the timing of these life events, migrations, and egg laying, and flowering and so on are changing, but they're changing at different rates, and that makes an ecosystem that has evolved in a cooperative way over the last couple thousand, or 10,000, or 100,000 years — it throws it out of kilter."
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