Is Human Activity Really to Blame for Climate Change? How Did Venus Get So Hot?

venusandearth

A recent debate between candidates for Congress in the Wisconsin’s 1st District — U.S. Rep. Paul Ryan, R-Janesville, and Democratic challenger Rob Zerban — included questions about the role of human beings in producing discernible changes in the climate over the last 150 years.

Unfortunately, this question, which is a matter of evidence, analysis and conclusion as all scientific questions are, has become a source of partisan political divide.

The Intergovernmental Panel on Climate Change (IPCC), a scientific body created by the United Nations to inform the UN regarding “scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change,” has issued five reports on this question since 1990.

These reports are a synthesis of many hundreds of peer-reviewed scientific studies on the issue.

With each successive report — they have been issued in 1995, 2001, 2007 and 2014 — the IPCC has increased the certainty of its conclusions.

The language in these reports has changed from “the balance of evidence suggests a discernible human influence on global climate” (1995) to “most of the observed warming is likely (a greater than 66 percent chance) due to human activities” (2001) to warming “over the last 50 years is very likely (a greater than 90 percent chance) due to human activities” to “It is extremely likely (a 95-100 percent chance) that human influence was the dominant cause of global warming between 1951-2010.”

This makes two things quite clear.

First, that scientists are a skeptical bunch and will move toward increased certainty only as evidence accumulates in favor of that conclusion.

Second, that human-induced global warming is a reality with which we must reckon.

During the debate, when asked if humans have a role in global warming, Ryan answered, “I don’t know the answer to that question. I don’t think science does either.”

He may well be correct in his first response, but he is certainly wrong in his second.

Article by Steve Ackerman and Jonathan Martin who are professors in the University of Wisconsin’s Department of Atmospheric and Oceanic Sciences in Madison, Wisconsin.

The above article was published in the Wisconsin State Journal print edition on October 20, 2014.

The IPCC also says “climate change is not a far-off problem. It is happening now and is having very real consequences on people’s lives. Climate change is disrupting national economies, costing us dearly today and even more tomorrow”, the IPCC states.

Astrobiologist David Grinspoon believes that scientists should look at our neighboring planets to help understand the perils of global warming. “It seems that both Mars and Venus started out much more like Earth and then changed. They both hold priceless climate information for Earth.”

The atmosphere of Venus is much thicker than Earth’s. Nevertheless, current climate models can reproduce its present temperature structure well. Now planetary scientists want to turn the clock back to understand why and how Venus changed from its former Earth-like conditions into the inferno of today.Climate scientists believe that the planet experienced a runaway greenhouse effect as the Sun gradually heated up. Astronomers believe that the young Sun was dimmer than the present-day Sun by 30 percent. Over the last 4 thousand million years, it has gradually brightened. During this increase, Venus’s surface water evaporated and entered the atmosphere.

“Water vapor is a powerful greenhouse gas and it caused the planet to heat-up even more. This is turn caused more water to evaporate and led to a powerful positive feedback response known as the runaway greenhouse effect,” says Grinspoon.

We have to make sure nothing like a runaway greenhouse effect doesn’t get started on Earth. Hopefully, it has not already started.

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About Mike Neuman

Environmentalist; Father; Senior Citizen; Husband, School Crossing Guard; Green Bay Packer Fan; Wisconsin Badger Fan; Animal Lover; Humanitarian

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