To survive the era of global warming vertebrate species must somehow dramatically accelerate their natural pace of evolution – or risk going extinct.
According to a study published in the journal Ecology Letters, species would have to evolve about 10,000 times faster than they have in the past to adapt to the rapid climate change expected in the next century. Scientists analyzed how quickly 540 species of amphibians, reptiles, birds, and mammals have adapted to climate change in the past. They found that species usually adapt to different climactic conditions at a rate of about 1 °C per million years. Then they compared that with atmospheric scientists’ prediction that global temperatures could increase by as much as 4 °C over the next 100 years. Obviously there’s a bit of a gap. “What that suggests overall is that simply evolving to match these conditions may not be an option for many species,” says study co-author John J. Wiens of the University of Arizona.
Wiens says that in the absence of evolutionary changes, species can survive the dislocations of a hotter planet by moving to higher latitudes or higher elevations. He acknowledges, however, that moving might not be an option for many species, especially tropical ones, and that barring that option, extinction is the most likely outcome. “Moving may require unimpeded access to habitats that have not been heavily disturbed by humans,” Wiens says. “Or consider a species living on the top of a mountain. If it gets too warm or dry up there, they can’t go anywhere.”
Well, at least one species is expected to thrive on an altered planet: poison ivy.
photo Doug McAbee
Researchers with the US Department of Agriculture say laboratory and field studies show that poison ivy is advancing with climate change and that its irritating oils are becoming even more potent. Already, poison ivy’s growth and potency has doubled since the 1960s. Pan-sized leaves are now common, and the vine has expanded its range into new woodlands. Poison ivy is expected to gain even more strength and a broader range as the amount of CO2 in the atmosphere continues to grow.
“Poison ivy and vines in general really, really benefit from higher atmospheric concentrations of CO2,” says Jacqueline Mohan, a professor of biology at University of Georgia who participated in the USDA study. “Vines use the infrastructure of trees, which means they can use carbohydrates generated from photosynthesis to make bigger, greener leaves.”
Mohan says surveys of forest plants in South Carolina showed poison ivy to be one of only a few plants that is becoming more abundant in coastal plain forests. “It’s getting happier and nastier,” she says.
Hotter temperatures and more carbon dioxide are also benefitting another plant that Americans love to hate: kudzu.
Some good news on the climate change front: The US is following through on a commitment to stop funding new coal plants overseas.
In his major climate change speech in June, President Obama called for an end to public financing of new coal plants “unless they deploy carbon-capture technologies, or there’s no other viable way for the poorest countries to generate electricity.” The pledge marked a retreat from the US’ past support for fossil fuel-related projects in poorer nations. In 2011, for example, the Export-Import Bank of the United States loaded $805 million to South Africa to build a massive coal-fired power plant there.
In July the Export-Import Bank’s board met to consider a proposed 1,200 megawatt coal-fired power plant in Vietnam. In a letter to the president, environmental groups said the decision would be “the first crucial test case” for Obama’s commitment. He passed. The Ex-Im Bank voted against funding the new coal plant in Vietnam.
Daphne Wysham of the Institute for Policy Studies, who for 16 years has been fighting against public financing for fossil fuel projects, was elated. “Hopefully, this is the dawn of a new day, when public financing of coal mines and power plants around the world is no longer acceptable,” she said.
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