Climate Tipping Points Near. Will Hit Tropics First

Brennan Linsley/AP - Giant ducts carry superheated steam from within a volcanic field to the turbines at a power plant in Iceland.  In a recent study, scientists predict that tropical cities will feel the first effects of climate change in as soon as seven years. Cities such as Reykjavik in Iceland will see changes much later, by 2066.

By Lenny Bernstein, Published: October 9, 2013

Locations around the globe will soon reach climatic tipping points, with some in tropical regions — home to most of the world’s biodiversity — feeling the first impacts of unprecedented eras of elevated temperatures as soon as seven years from now, according to a study released Wednesday.

On average, locations worldwide will leave behind the climates that have existed from the middle of the 19th century through the beginning of the 21st century by 2047 if no progress is made in curbing emissions of heat-trapping greenhouse gases, said researchers at the University of Hawaii at Manoa who sought to project the timing of that event for 54,000 locations.

Graphic

This global-warming map shows the predicted dates that temperatures in selected cities will exceed historical norms.

If they are correct, the transition will occur by 2020 in Manokwari, Indonesia; by 2023 in Kingston, Jamaica; by 2029 in Lagos, Nigeria; by 2047 in Washington; by 2066 in Reykjavik, Iceland; and by 2071 in Anchorage.

“The boundary of passing from the climate of the past to the climate of the future really happens surprisingly soon,” said Christopher Field, director of the Department of Global Ecology at the Carnegie Institution for Science. Field was not part of the research team but has read the study, published in the journal Nature.

Researchers said at a news briefing that their estimates are “conservative,” based on mountains of data from 39 models and accurate within five years in either direction for any of the locations they studied.

Although scientific research shows that more warming occurs nearer to Earth’s poles — and the melting of arctic ice sheets is the iconic image of a warming planet — the tropics are especially vulnerable because even a small change in climate will affect a wide range of species. It is also alarming because the area around the equator is home to billions of people in poor nations with fewer resources to help them cope.

The study is hardly the first to document the steady march toward hotter temperatures around the globe. Less than two weeks ago, the Intergovernmental Panel on Climate Change (IPCC) released its fifth report, describing a planet that is warming at an accelerated pace because of human activity. The past three decades have been the hottest since 1850, according to the panel established by the United Nations, which added that warming and sea-level rise will continue through the 21st century.

But by predicting the tipping point when traditional climates will be replaced by hotter futures, the new study’s group — led by Camilo Mora, an assistant professor in the University of Hawaii at Manoa geography department — provided a fresh way to look at a problem that often is seen as a global phenomenon, except by authorities who must respond to the increasing toll of floods, droughts, wildfires and severe weather, experts said.

“I think people don’t appreciate the fact that one of the metrics we are most familiar with, and definitely have the most difficulty dealing with, extreme heat, is coming down the track,” said Michael Oppenheimer, a professor of geosciences at Princeton University.