Monday, March 31, 2014

IPCC latest: We were way too conservative in climate predictions

At a utility conference on Maui last week, someone complained that the United States has had three hundred-year storms in the last decade.

Last Saturday, a downpour atop Haleakala caused a flash flood that ripped out the highway near Ulupalakua.

Do you get the feeling that more of this kind of stuff is happening than used to? 

Get used to that feeling.

The Intergovernmental Panel on Climate Change has just reported that things are getting worse way faster than their earlier predictions forecast.

If you want to read it for yourself (it is not easy reading), look here.
At a minimum, the headings and the graphics are interesting to view. See key examples in the summary for policy makers

The report’s authors say the poor will suffer disproportionately, but everybody will be impacted.

To the degree that the climate scientists were cautious in their assessment earlier, they are not cautious any longer. The change is upon us, they say: “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. 

“The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.”

The oceans have warmed, the earth’s surface has warmed and the atmosphere has warmed, the authors say. They generally say they have “high confidence” in those statements. Most of the additional heat—about 60 percent of it—is stored in the upper levels of the ocean.

And about those storms, rain events, and the like? “Changes in many extreme weather and climate events have been observed since about 1950.”

Sea levels are now rising faster than they have in 2000 years. 

The Hawai`i-centric impacts? Among the key ones may be rainfall and sea level. 

We’ve already heard that we are experiencing drier weather in Hawai`i, but also that the rain may come in more severe pulses. I thought about that as I watched a brown river surging across the Ulupalakua highway. Says the report: “Extreme precipitation events over most of the mid-latitude land masses and over wet tropical regions will very likely become more intense and more frequent by the end of this century, as global mean surface temperature increases.”

Sea level: By the last two decades of this century, the current best assessment is that sea levels will be 10 to 21 inches higher than they are now. And they are now 7 inches higher than they were at the start of the last century. That's likely one of the reasons that beachfront houses are falling into the ocean on Kaua`i and O`ahu.

The report is reasonably confident of that amount of sea level rise, but not extremely confident, in part because more moisture in the atmosphere could dump more snow on polar regions, locking up some of that water. 

That said, sea level rise was faster in the last 30 years than in the period before, and is likely to continue , to increase in the speed of the rise. 

“The rate of sea level rise will very likely exceed that observed during 1971 to 2010 due to increased ocean warming and increased loss of mass from glaciers and ice sheets,” the summary says.

And we have locked out grandchildren and their grandchildren into this climate madness. Even if the world were to stop the rampant production of carbon dioxide, one of the primary causes of climate change, we’re stuck now.

“Cumulative emissions of CO2 largely determine global mean surface warming by the late 21st century and beyond. Most aspects of climate change will persist for many centuries even if emissions of CO2 are stopped. This represents a substantial multi-century climate change commitment created by past, present and future emissions of CO2,” it says.

This is all not to say there isn’t still some scientific controversy about the report. Dutch scientist Richard Tol withdrew from the panel in protest of what he called its alarmist tone. That is not because he disagrees with how significant climate change will be, but rather because he feels that in many ways it might be a good thing.

Reuters quoted Tol: ”It is pretty damn obvious that there are positive impacts of climate change, even though we are not always allowed to talk about them.”

Most of the involved scientists disagree with him generally, and argue that the negatives far outweigh likely positives.

If we keep dumping carbon dioxide into the atmosphere, the greenhouse effect continues, and it just keeps getting warmer.

Want a scary scenario? National Geographic has an interactive map of what the world looks like if ALL the ice melts. Ocean levels rise 216 feet, and North America gets skinnier. Florida’s gone. The Eastern Seaboard is gone. The California Central Valley is a bay.

© Jan TenBruggencate 2014

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