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Today’s Hot Will Be Tomorrow’s Cool, Research Shows
October 21, 2013

Today’s Hot Will Be Tomorrow’s Cool, Research Shows

By Charlene Porter
IIP Staff Writer
18 October 2013

The damage done to delicate coral reef ecosystems has been widely documented.

The weather that humans considered hot over the past century or so will be the kind of weather that future generations will find to be cool, according to new climate science reported in the journal Nature October 10.

A research team at the University of Hawai’i at Mānoa (UH-Mānoa) identified points when temperatures will reach “climate departure” in the future. A climate departure is when the average temperature at a location of its coolest year from then on is projected to be warmer than the average temperature of its hottest year between 1860 and 2005.

The UH-Mānoa group created an index of locations worldwide, marking the years cities across the globe will cross the threshold of climate departure.

Calculating an average for all the various locations, 2047 will be the year by which climates have become radically different, according to the study authors.

“The results shocked us,” said lead author Camilo Mora, from UH-Mānoa’s College of Social Sciences’ Department of Geography. “Regardless of the scenario, changes will be coming soon. Within my generation, whatever climate we were used to, will be a thing of the past.”

Within 35 years, even the lowest monthly dips in temperatures will be hotter than the hottest spells that we think of today, according to the researchers.

As with calculation of any average, extremes in the arrival of climate departure fall on both sides of 2047, sooner and later. The world’s tropical regions will be the first to encounter these unprecedented high temperatures, the researchers say, which could be especially hard on the natural world. Tropical species are unaccustomed to climate variability experienced by those living through hot summers and cold winters every year. For that reason, tropical species could be more vulnerable to relatively small changes, causing damage to biologic diversity.

Reaching the point of climate departure could have difficult effects on food and water supplies, economic performance and disease occurrence, the UH-Mānoa study finds.

“Our results suggest that countries first impacted by unprecedented climate are the ones with the least capacity to respond,” said co-author Ryan Longman.

While the data may conjure visions of disaster movies to the layman, the science reveals alternatives. The more steps taken now to reduce carbon dioxide emissions and slow the trajectory of a warming climate, the more time humans, plants and animals will have to adapt and prepare for life in a different environment.

The sophisticated climate projections scientists produce now consider degrees of emissions levels, and calculate best and worst possibilities. With regard to the occurrence of climate departure in the tropics, a best-case scenario will affect the lives of 1 billion people. Five billion could be adversely affected in a worst-case scenario.

The report “builds on earlier work but brings the biological and human consequences into sharper focus,” said Jane Lubchenco, an Oregon State University marine ecologist and a former administrator of the federal National Oceanic and Atmospheric Administration. “It connects the dots between climate models and impacts to biodiversity in a stunningly fresh way.”

The Climate Action plan announced by the Obama administration in June aims to accelerate action to reduce greenhouse gas (GHG) emissions, encourage energy efficiency and develop wider use of sustainable non-carbon energy sources across the economy. The plan is also keenly focused on the need to move rapidly to lessen the rate of GHG emissions and slow the pace of global warming as identified in the worst-case scenarios.

“We don’t have time for a meeting of the Flat Earth Society,” said President Obama in his June speech announcing the plan and sarcastically pointing to those who still cast doubt on the science of climate change. An overwhelming majority of climate scientists concur that the atmosphere and the oceans are getting warmer, with a 95 percent certainty that human activity is driving the change.

The Intergovernmental Panel on Climate Change (IPCC) working group is the world’s most expert panel studying the matter, involving scientists from 195 countries. The panel released its latest projections in late September finding that, “Warming in the climate system is unequivocal.”

Drawing on millions of atmospheric and oceanic observations and citing more than 9,000 previously published scientific papers, the IPCC report projects that global surface temperatures by the end of the 21st century will be 2 degrees Celsius higher than they were in 1900.

Moderating that increase is possible, the experts say. The United States, more than 30 other nations and the European Commission are partners in the Climate and Clean Air Coalition to Reduce Short Lived Climate Pollutants. They are committed to actions that could decrease warming by 0.5 degrees Celsius by 2050. This plan focuses on making big reductions quickly in short-term pollutants, those that have a shorter life in the atmosphere. Sharp reductions in methane emissions and soot production will help arrest global warming, research shows.

The U.S. Climate Action Plan aims to reduce the nation’s carbon emissions by 3 million metric tons by 2030, an amount that is equivalent a year’s worth of emissions generated by electricity production.


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