Global implications
MEXICO CITY – Rising global temperatures could melt Latin America’s glaciers within 15 years, cause food shortages affecting 130 million people across Asia by 2050, wipe out Africa’s wheat crop and create serious shortages in North American cities that rely on melting snow for water, according to a U.N. report released Tuesday.
The report, written and reviewed by hundreds of scientists, outlined dramatic effects of climate change including rising sea levels, the disappearance of species and intensifying natural disasters. It said 30 percent of the world’s coastlines could be lost by 2080.
Scientists with the Intergovernmental Panel on Climate Change outlined details of the report in news conferences around the world Tuesday, four days after they released a written summary of their findings. The report is the second of three being issued this year; the first dealt with the physical science of climate change and the third will deal with responses to it.
North America will not escape the impact of climate change, and the impact will be felt from Florida and Texas to Alaska and Canada’s Northwest Territories, the panel said.
“Canada and the United States are, despite being strong economies with the financial power to cope, facing many of the same impacts that are projected for the rest of the world,” Achim Steiner, executive director of the U.N. Environment Program which co-founded the panel, said in a statement.
“Heavily utilized water systems of the western U.S. and Canada, such as the Columbia River, that rely on capturing snowmelt runoff, will be especially vulnerable,” the report said.
A temperature increase of a few degrees by the 2040s is likely to sharply reduce summer flows, at a time of rising demand, it said.
By then, the panel estimated, Portland will require more than 26 million additional cubic meters of water as a result of climate change and population growth, but the Columbia River’s summer supply will have dropped by an estimated 5 million cubic meters.
North American producers of wood and timber could suffer losses of between $1 billion and $2 billion a year during the 21st century if climate change also sparks changes in diseases, insect attacks and forest fires, the panel said.
In Mexico City, scientists predicted, global warming could cost the Brazilian rain forest up to 30 percent of its species and turn large swaths into savannah. They said ocean levels are projected to rise 4.3 feet by 2080 and flood low-lying cities including Rio de Janeiro, Brazil, and Buenos Aires, Argentina.
Polar ice caps will likely melt, opening a waterway at the North Pole and threatening to make the Panama Canal obsolete, IPCC member Edmundo de Alba said.
Warmer waters will spawn bigger and more dangerous hurricanes that will threaten coastlines not traditionally affected by them.
Latin America’s diverse ecosystems will struggle with intense droughts and flooding and as many as 70 million people in the region will be left without enough water, according to the report.
“What’s clear is places suffering from drought are going to become drier, and places with a large amount of precipitation are going to see an increase in precipitation,” de Alba said.
The report said Africa is most vulnerable to the effects of climate change.
The fallout from a swiftly warming planet – extreme weather, flooding, outbreaks of disease – will only exacerbate troubles in the world’s poorest continent, said Anthony Nyong, one of the lead authors.
Wheat, a staple in Africa, may disappear from the continent by the 2080s, the report said.
Africa has “the least responsibility for climate change and yet it is perversely the continent with the most at risk if greenhouse gases are not cut,” said Steiner. In Asia, nearly 100 million people will face the risk of floods from seas that are expected to rise between 0.04 inches to 0.12 inches annually, slightly higher than the global average.
The report suggests that a 3.6-degree increase in mean air temperature could decrease rain-fed rice yields by 5 percent to 12 percent in China. In Bangladesh, rice production may fall by just under 10 percent and wheat by a third by the year 2050.
The drops in yields combined with rising populations could put close to 50 million extra people at risk of hunger by 2020, 132 million by 2050 and 266 million by 2080, the report said.
In Europe’s Mediterranean region, climate change is expected to sap electric power generation, raise sea levels in coastal regions, reverse tourism trends and leave millions of people with water shortages, scientists said.
For Australians and New Zealanders, the higher temperatures will be felt mostly through more extreme weather.