The Intergovernmental Panel on Climate Change has just issued its Fifth Assessment Report summarizing the best scientific information about global warming that is available in 2014. Key findings are:
It is extremely likely that humans are the dominant cause of warming since the mid-20th century.
Each of the past three decades has been successively warmer than the preceding decades since 1850.
Oceans absorb more than 90% of the heat.
Land temperatures remain at historic highs while ocean temperatures continue to climb.
Oceans will continue to warm during the 21st century.
Global mean sea level will continue to rise during the 21st century.
It is very likely that the Artic sea ice cover will continue to shrink and thin as global mean surface temperature rises.
Some of the changes in extreme weather and climate events observed since about 1950 have been linked to human influence.
The globally averaged temperature shows a warming of .85 degrees centigrade over the period 1880 – 2012. And 65% of the carbon budget compatible with limiting future temperature to an overall 2 degrees C increase has already been used.
Energy production remains the primary driver of greenhouse gas emissions.
Measures exist to achieve the substantial emissions reductions required to limit likely warming to 2 degrees C.
Delaying mitigation will substantially increase the challenges associated with limiting warming to 2 degrees C.
I consider the above information from the IPCC report to be noncontroversial and providing overwhelmingly strong evidence that global warming is taking place. Next question: What do we do about it? This will be the subject of my next post!
“Risk is like fire: If controlled it will help you; if uncontrolled it will rise up and destroy you.” Theodore Roosevelt, 1858 – 1919
Just a few days ago I featured an Op Ed column in the New York Times “The Coming Climate Crash” by Henry Paulson, the former Secretary of the Treasury. He discusses global warming as an economic issue. The increasing number of severe storms, deeper droughts, longer fire seasons and rising sea levels it will cause will wreak tremendous economic damage on our country and the whole world as well. A new report, “Risky Business” produced by the Risky Business Project, elaborates much further on this theme. “The American economy is already beginning to feel the effects of climate change. These impacts will likely grow materially over the next 5 to 25 years and affect the future performance of today’s business and investment decisions in the following areas: coastal property and infrastructure (damaged by storm surges and higher sea levels); agriculture (disrupted by higher temperatures); energy (costs will go up to provide more cooling).”
In addition to the large scale economic effects referred to above, global warming will affect each of us in a very direct way. For example, in Omaha NE where I live, in just a few short years the current average of about 10 days per summer with a temperature over 95 degrees F, will increase to about 25 such summer days.
All of these effects are assuming that we continue on our present course of rapidly increasing CO2 build up in the atmosphere. We do have a choice in this matter. We can cut back but it will take a big effort to accomplish this. The whole world needs to cut back and it is up to the U.S. to lead the way.
Republicans need to step forward on global warming. It is highly irresponsible to say that any anti-carbon measures we take will just hurt our economy and ignore all of the harmful effects of proceeding on our present course. It is also irresponsible to say that we can’t act unless everyone else does too. If we are exceptional, and I agree that we are, then it is up to us to set an example for the whole world.
We need fiscal conservatives in office to address our very serious deficit and debt problems. But fiscal conservative have to win the trust of a wider group of voters to show that they are deserving of broader support.
A few days ago I made the argument that “we need a carbon tax” because global warming is real and our response to it should not be defaulted to regulatory action by the EPA and individual states acting on their own. Just two days ago the U.S. Global Change Research Program released a voluminous new report, the “Third National Climate Assessment”, giving many examples of how dramatically global warming is already affecting life in the United States as well as all over the world. Perhaps the most direct effect in the U.S. is an increase in average temperatures of almost 2 degrees Fahrenheit since 1900. This means that summers are longer and hotter and that winters are shorter and warmer, on average. Hotter temperatures mean that there is more moisture in the atmosphere and rain comes in heavier downpours. It is going to be harder and harder for doubters to deny the accumulating evidence. Global average temperatures have also increased by almost 2 degrees F in the past century. The most dramatic, and visible, evidence worldwide for climate change is the shrinking of the artic polar icecap measured each year in September. Although the ice extent fluctuates from one year to another, the pattern of decline, as shown below, is clearly evident. A worldwide response is urgently needed and the wealthiest country in the world should step up to the plate and lead the way. A carbon tax does not mean an end to using to using fossil fuels but simply provides a strong incentive, without government picking winners and losers, to cut back on carbon emissions. We can be confident that, with a strong economic incentive, American technology will figure out how to remove carbon from fossil fuels during combustion.
The sooner we begin a program along these lines, the better off we will all be in the very near future as the world continues to get warmer.