CAPE CANAVERAL, FLORIDA – Last year was Earth’s hottest on record, two U.S. government agencies said Friday — new evidence that people are disrupting the climate by burning fossil fuels that release greenhouse gases.
The White House said the studies, by the space agency NASA and the National Oceanic and Atmospheric Administration (NOAA), showed climate change is happening now and that action is needed to cut rising greenhouse gas emissions.
The 10 warmest years since records began in the 19th century have all been since 1997, the data showed. Last year was the warmest, ahead of 2010, undermining claims by some deniers that global warming has stopped in recent years.
Record temperatures in 2014 were spread around the globe, including most of Europe and northern Africa, the western United States, far eastern Russia and western Alaska, parts of interior South America, parts of eastern and western coastal Australia, NASA and NOAA said.
“While the ranking of individual years can be affected by chaotic weather patterns, the long-term trends are attributable to drivers of climate change that right now are dominated by human emissions of greenhouse gases,” said Gavin Schmidt, director of NASA’s Goddard Institute of Space Studies in New York. “The data shows quite clearly that it’s the greenhouse gas trends that are responsible for the majority of the trends,” he told reporters.
Emissions are still rising, “so we may anticipate further record highs in the years to come.”
U.N. studies show there already are more extremes of heat and rainfall and project ever more disruptions to food and water supplies. Sea levels are rising, threatening millions of people living near coasts, as ice melts from Greenland to Antarctica.
Next December, representatives of about 200 governments will meet in Paris to try to reach a deal to limit global warming by shifting to renewable energy sources. China and the United States, the top emitters of greenhouse gases, say they are cooperating more to achieve a U.N. accord.
The new data are “another reminder that climate change is not a problem for the future — it’s happening here and now, and we can’t wait to take action,” a White House official said in a statement.
Opponents of the proposed Keystone XL pipeline, which would transport Canadian crude oil across the United States, said the new data make preventing the pipeline’s construction all the more pressing.
But Sen. James Inhofe, a Republican who is the Senate’s leading climate change denier, said the temperature difference between 2014 and 2010 was so insignificant as to prove there is no need for more stringent regulations by the U.S. Environmental Protection Agency. “Human activity is clearly not the driving cause for global warming and is not leading our planet to the brink of devastation that many alarmists want us to believe,” he said.
The U.N.’s Intergovernmental Panel on Climate Change (IPCC) says it is at least 95 percent probable that human activities, rather than natural variations in the climate caused by factors such as sunspots, are to blame for rising temperatures.
A Paris deal will be hard to achieve because curbs on using fossil fuels are unpopular in many nations. Low oil prices may also discourage a shift to cleaner wind and solar power.
“The political challenges of organizing countries to respond, particularly through the U.N. process, remain very high,” said Michael Levi, a fellow on energy and environment at the Council on Foreign Relations in New York.
Rowan Sutton, director of climate research at Britain’s National Centre for Atmospheric Science at the University of Reading, said a single year does not mean much because it might be a freak hot year. “But the fact that now 14 of the 15 warmest years on record have occurred since the turn of the century shows just how clear global warming has become,” he said.
Even so, temperatures have not risen as fast as they did in the 1980s or 1990s, taking an unusually warm 1998 as a starting point. The IPCC has described it as a hiatus in warming.
Since 1880, Earth’s average surface temperature has warmed by about 1.4 degrees Fahrenheit (0.8 degree Celsius), NASA said. The NASA and NOAA analyses showed that the world’s oceans all warmed last year, offsetting somewhat more moderate temperatures over land. The average temperature across global land and ocean surfaces last year was 1.24 degrees F (0.69 degree C) above the 20th-century average, NOAA said.
The scientists noted that the record was set in a year that did not have the weather pattern known as El Nino, which can heat up the atmosphere and has been a factor in many past record-setting years, including 1998.
The United Nations says it is already clear that promises for emissions curbs at the Paris summit will be too weak to get on track for a U.N. goal of limiting global warming to 2 degrees C (3.6 F) above pre-industrial times.