Researchers at Lawrence Livermore National Laboratory predicted a significant increase in average air temperature over the long term – iceless polar regions, 40 degrees Fahrenheit warmer, and a 20-foot rise in ocean sea levels by the year 2300.

A new study uses a series of interlinked computer models, including a LLNL model that connects carbon input with climate, an ocean-atmosphere model from National Center for Atmospheric Research, and the Parallel Ocean Program (POP) from Los Alamos National Laboratory that simulates ocean circulation.

“The study will at least shift the focus of debate away from the question whether climate change will happen or not,” said lead author Govindasamy Bala of the LLNL Energy and Environment Directorate. “We may still be OK by 2050, let’s say, but in the long term, if we keep on with business as usual, the consequences will be very severe.”

Recent studies have concentrated on a modest warming trend over the next century, but the new projection looks beyond the horizon at the 22nd and 23rd centuries when warming impacts have built up a head of steam, nearly quadrupling the carbon dioxide in the atmosphere from 380 parts per billion to 1,423 ppb in 300 years.

If you have any perception of the computing/programming horsepower at the two National Labs — Lawrence Livermore and Los Alamos — you’ll appreciate what this means to the question.

Phil Jones, climate model group leader at LANL, called the paper both interesting and original.

“There haven’t been too many studies published like this. One thing they do is integrate climate change out to the far future, a hundred years beyond where we usually go,” he said. “In most climate models, we impose a certain carbon dioxide concentration from the atmosphere. Here we’re starting to get the actual feedback from that, how much the land and oceans are taking up.”

LANL has added new tools to its climate model, including a full ocean biochemistry and geosystems model that will enhance ocean ecosystem predictions and chemical feedbacks including carbon as well as aerosols, Jones said.

Among plans for the future, Bala said his group would begin to incorporate land use changes that are not included now.

“What if you plant forests? Will that slow down global warming?” Bala asked. Forests take up carbon dioxide, but they might also darken the landscape, absorbing more heat.

Seeing consequences over the long time scale is important because the system has a long time delay from the time you pick up the early signals, Bala said.

“If you disturb and continue to disturb, by that time it may be too late.”

Thanks, Khalil

Update: This story hit the international media, today.