Ocean Warming May Be Drastically Underestimated
The oceans have been warming much faster than previously data showed, according to two new studies.
New climate model and satellite data suggests that ocean warming from 1970 to 2004 in the upper levels of Southern Hemisphere oceans has been massively underestimated. The findings are reported in two new studies in the journal Nature Climate Change.
"This underestimation is a result of poor sampling prior to the last decade and limitations of the analysis methods that conservatively estimated temperature changes in data-sparse regions," said oceanographer Paul Durack, from Lawrence Livermore National Laboratory, and the lead author of one of the papers.
The findings are important because oceans absorb about 90 percent of the planet's excess heat, and the Southern Hemisphere accounts for 60 percent of the world's oceans. The latest data suggests that the planet is warming faster than previously thought.
"By using satellite data, along with a large suite of climate model simulations, our results suggest that global ocean warming has been underestimated by 24 to 58 percent," Durack said in a press release. "The conclusion that warming has been underestimated agrees with previous studies, however it's the first time that scientists have tried to estimate how much heat we've missed."
In 2004, researchers began collecting more accurate measurements by deploying 3,600 robotic measuring devices, called Argo floats, which relayed information on the heat stored in the upper layers of the world's ocean currents.
Determining how fast the oceans are warming relates directly to how fast the atmosphere is warming and how much sea levels will rise, the researchers wrote.
"Our other new study on deep-ocean warming found that from 2005 to the present, Argo measurements recorded a continuing warming of the upper-ocean," said co-author Felix Landerer of NASA's Jet Propulsion Laboratory, who contributed to both studies. "Using the latest available observations, we're able to show that this upper-ocean warming and satellite measurements are consistent."
More than 3,600 robotic floats are taking measurements in the upper layers of the world's ocean currents.
The effects of global warming are frequently projected decades into the future, but two recent reports -- one from the
and the other
-- put into sharp focus visible consequences of our warming planet. An increase in temperature, extreme weather, loss of ice and rising sea level are just a few of changes we can measure right now. Let's take a look at some of the most concerning trends.
Glaciers are shrinking worldwide and permafrost is thawing in high-latitude and high-elevation areas, reports this year's Fifth Assessment Report from the Intergovernmental Panel on Climate Change.
Only a few extinctions are attributed to climate change, reports the IPCC, but climate change that occurred much more slowly, over millions of years, caused major ecosystem shifts and species extinctions. Land and sea animals are changing their geographic ranges and migratory patterns due to climate change.
Sea level around the world has increased by about 8 inches since 1880, reports the 2014 National Climate Assessment, which projects a 1 to 4 foot rise by the end of the century.
Excess CO2 is dissolving in the ocean and decreasing the pH of seawater. The ocean is about 30 percent more acidic than it was in pre-industrial times. More acidity in the oceans makes it harder for animals to form calcium carbonate shells and skeletons and erodes coral reefs.
The probability of a Sandy-like storm deluging New York, New Jersey and other parts of the East Coast has nearly doubled compared to 1950, according to the American Meteorological Society. Even weaker storms will be more damaging now than they were 10 years ago because of rising sea levels. Superstorm Sandy cost the nation $65 billion, according to the 2014 National Climate Assessment, and 2012's Hurricane Isaac cost $2.3 billion.
The global sea level rises along with the temperature for two major reasons. For one, heat causes water to expand, which causes the existing water to take up more space and encroach on the coast. At the same time, ice at the poles and in glaciers melts and increases the amount of water in the oceans.
Across the United States, heavy downpours are on the rise, especially in the Northeast and Midwest. Increases in extreme precipitation are expected for all U.S. regions, reports the 2014 National Climate Assessment.
The most recent IPCC report states with "very high confidence" that current climate-related extremes like heat waves, droughts, floods, cyclones and wildfires are showing that countries around the world, at all development levels, are significantly unprepared. The American Meteorological Society estimates that approximately 35 percent of the extreme heat in the eastern United States between March and May 2012 resulted from human activities' effects on climate. The AMS warned that deadly heat waves will become four times more likely in the north-central and northeastern United States as the planet continues to warm.