Far North Science

Erosion and melting permafrost
topples Shismaref house
Shishmaref Relocation Coalition

If people want to slow global warming and avoid catastrophic changes to the Earth’s ecology, they must cut emissions — even if it means taxing carbon and slowing the world economy.

The recommendations came from the third chapter of the fourth assessment by the Intergovernmental Panel on Climate Change, a United Nations group that periodically marshals the world’s top climate scientists to evaluate the status and risks of climate change.

The 35-page summary for policy makers was released last week, explaining how people and their governments can mitigate the rise in greenhouse gases. It boiled down to this:

It’s the carbon, stupid.

We must reduce emissions or suffer. And that will mean swallowing an economic pill: The IPCC report suggested that each ton of carbon produced by combustion engines and power plants be taxed so that it costs an extra $50 to $100 — as much as a $1 per gallon on gas. This incentive to reduce emissions could ultimately slow the world’s economy by a few percentage points.

The alternative may be unthinkable: The global concentrations of carbon dioxide, now higher than they have been in 650,000 years, could keep rising until they are 90 percent beyond 1970’s levels, triggering vast shifts in climate and a devastating rise in sea level.

Global temperature rise
Credit: NCDC-NOAA

The planet will experience unprecedented stress — heat waves, droughts, floods, hunger, dying species, disappearing glaciers and an ocean that grows ever more acidic. By 2050, some 200 million people could be displaced by rising sea levels. Some 40 species of animals and plants could be gone forever.

“We are on the edge of the greatest die-off humanity has ever seen,” James Lovelock told the London Times. “We will be lucky if 20 percent of us survive what is coming. We should be scared stiff.”

Adapting to rising temperatures and environmental damage will cost billions. And it’s the poorest countries that will suffer most — as well as Native people who gather food for subsistence across the Arctic, where the changes will appear first.

This latest report is included of the climate panel’s most recent assessment, the fourth since it was created in 1988 by the United Nations to monitor climate.

The first summary for Climate Change 2007, released in February, called evidence of global warming “unequivocal” and rated human-generated emissions of greenhouse gases “very likely” the main driver in the Earth’s fast changing climate.

The second chapter concentrated on Climate Change Impacts, Adaptation and Vulnerability — presented to world media in Brussels in early April.

“In the Polar Regions, the main projected biophysical effects are reductions in thickness and extent of glaciers and ice sheets, and changes in natural ecosystems with detrimental effects on many organisms including migratory birds, mammals and higher predators,” the second report argued. “In the Arctic, additional impacts include reductions in the extent of sea ice and permafrost, increased coastal erosion, and an increase in the depth of permafrost
seasonal thawing.”

It doesn’t have to happen, according to the third report. Making wide cuts in the tonnage of greenhouse gases like carbon dioxide is doable and has precedent.

Andrew Revkin, of the New York Times, quoted William Moomaw, a lead author of a chapter on energy options and a professor of international environmental policy at Tufts University. Moomaw said the transition ahead for the globe was not unlike the one made early in the 20th century. That people could make big cuts and adapt.

“Here in the early years of the 21st century, we’re looking for an energy revolution that’s as comprehensive as the one that occurred at the beginning of the 20th century when we went from gaslight and horse-drawn carriages to light bulbs and automobiles,” Dr. Moomaw said.

“In 1905, only 3 percent of homes had electricity. Right now, 3 percent is about the same range as the amount of renewable energy we have today. None of us can predict the future any more than we could in 1905, but that suggests to me it may not be impossible to make that kind of revolution again.”