The planet has a fever, but it's not too late to treat this global warming and the problems it spawns. That’s the message in a new report published in April by a panel of hundreds of climate scientists. The world may be able to avoid a crisis — but only by switching to less-polluting energy sources, it said. Sources of energy that belch huge amounts of greenhouse gases into the atmosphere, the report warned, must be kept to a minimum.
The scientists behind the latest report are part of the Intergovernmental Panel on Climate Change (IPCC). This group keeps tabs on the newest published research on climate and on how ecosystems are responding to it. They summarized its latest findings at an April 13 meeting in Berlin, Germany.
Their message isn't new. But evidence to support the scientists’ concerns about Earth’s climate is growing — and getting stronger — every year, the IPCC authors note.
The IPCC has been issuing reports since 1990. Its latest is focused on how people can limit the ongoing rise in surface temperatures across the globe. Greenhouse gases, such as carbon dioxide, trap heat in the atmosphere. That excess heat gets stuck close to the ground. As a result, the planet’s average temperature has been increasing since the Industrial Revolution in the early 1800s. That was when people started burning massive amounts of coal and other fossil fuels for power.
For more than a decade, IPCC scientists have warned that many people will suffer greatly if Earth’s average global temperature increases by more than 2° Celsius (3.6° Fahrenheit) over what was typical before the Industrial Revolution. But if people continue to pump greenhouse gases into the air at current rates, global temperatures could increase by as much as 7.8 °C (about 14 °F) by 2100, the new report points out.
Higher temperatures will bring more frequent heat waves and droughts and more intense storms. Such warmth could melt the polar ice caps. That would lead to catastrophic flooding in some coastal areas. Higher temperatures also can help to spread many types of infectious diseases, such as malaria and yellow fever, to regions that they do not now affect. These are just a few of the predicted impacts.
And increased heat isn’t the only concern. That’s why global warming is also known as climate change. The ocean, for instance, absorbs some of the extra carbon dioxide from the air. As a result, ocean water becomes more acidic. This process is known as acidification. That change in chemistry can have negative consequences for some sea creatures.
Most greenhouse gases are produced through the burning of fossil fuels, such as coal and natural gas. The IPCC scientists recommended that the best way to slow global warming by the year 2100 is to triple or quadruple the use of other, “greener” sources of power over the next 35 years. Embracing that shift should limit the amount of greenhouse gases in the air and stem the temperature rise.
Greener energy sources include renewables such as wind, sunlight and geothermal power. (They're “renewable” because the amount used is quickly replaced by natural processes. Fossil fuels, in contrast, are not replaceable. Once used, they are gone forever.) In terms of climate, greener energy also includes nuclear power, which produces few greenhouse gases. Even some coal-burning plants might be considered “green” if they capture and store the greenhouse gases they would otherwise have pumped into the air.
“There’s no one technology that’s going to do the whole thing or even half,” engineer Howard Herzog told Science News. At the Massachusetts Institute of Technology in Cambridge, Herzog is an expert on capturing and storing carbon.
For decades, the IPCC scientists’ message has been the same: The world’s average temperature is rising because the atmosphere is overloaded with greenhouse gases. Over that time, however, the amount of greenhouse gases being produced by human activities has not fallen. Nations are still burning lots of fossil fuels. The new report offers a plan for the future, but Herzog worries nothing will change. “The IPCC report is saying there’s going to be dire consequences,” he notes, and still “the response is business as usual.”
Ottmar Edenhofer worked on the new report. He's a professor of the economics of climate change at the Technical University Berlin. At a press conference, he said that he hoped the new report brings about the changes in government policy that are needed to make a difference. It’s still not too late, he says. The report “provides hope, modest hope” of that.
atmosphere The envelope of gases surrounding Earth or another planet.
acid A chemical substance that can dissolve some metals and that reacts with bases to form salts. Acids usually taste sour.
acidic An adjective for materials that contain acid. These materials often are capable of eating away at some minerals such as carbonate, or preventing their formation in the first place.
acidification A process that lowers the pH of a solution. When carbon dioxide dissolves in water, it triggers chemical reactions that create carbonic acid.
carbon dioxide A gas produced by all animals when the oxygen they inhale reacts with the carbon-rich foods that they’ve eaten. This colorless, odorless gas also is released when organic matter (including fossil fuels like oil or gas) is burned. Carbon dioxide acts as a greenhouse gas, trapping heat in Earth’s atmosphere. Plants convert carbon dioxide into oxygen during photosynthesis, the process they use to make their own food.
climate change Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.
fossil fuels Any fuel (such as coal, oil or natural gas) that has developed in the Earth over millions of years from the decayed remains of bacteria, plant or animals.
geothermal energy The internal heat of the Earth or other planet.
global warming The gradual increase in the overall temperature of Earth’s atmosphere due to the greenhouse effect. This effect is caused by increased levels of carbon dioxide, chlorofluorocarbons and other gases in the air, many of them released by human activity.
greenhouse gas A gas that contributes to the greenhouse effect by absorbing heat. Carbon dioxide is one example of a greenhouse gas.
Industrial Revolution A period of time in the early 1800s marked by new manufacturing processes and a switch from wood to coal and other fossil fuels as a main source of energy.
natural gas A mix of gases that developed underground, like crude oil (and often in association with crude oil) over, millions of years. Most natural gas starts out as 50 to 90 percent methane, along with small amounts of heavier hydrocarbons, such as propane and butane.
nuclear power Energy derived from processes that produce heat by splitting apart the nuclei of atoms (fission) or forcing atomic nuclei to merge (fusion). A nuclear power plant uses that heat to drive turbines that create electricity.
renewable energy Energy from a source that is not depleted by use, such as hydropower (water), wind power or solar power.
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