The climate change debate centers on whether human activities such as deforestation and burning fossil fuels are releasing more greenhouse gases, causing the average global temperature to rise.
On one side of the argument are 99.8 percent of climate change papers published in the last quarter century; on the other side is Sen. James Inhofe holding a snowball.
The increase in average global temperature over the last 200 years is the most in human history, and this trend began at the same time as the Industrial Revolution. Of course, one must always consider correlation and causation. There is a chart showing almost identical trends of string cheese sales and persons dying while getting out of bed. The difference here is that fewer trees and the burning of coal, gas, and oil releases more carbon dioxide, methane, and water vapor, which drives up temperature, so causation is a valid conclusion.
Not everyone agrees with this. Online, I found 176 objections to the notion of manmade climate change on one site alone. (This list and counter-arguments are here: http://tinyurl.com/2m24g8). So this will be an incomplete rundown, but I want to hit on some of the easier to explain.
The most common objection sarcastically declares, “I believe in climate change,” accompanied by symbols of the four seasons. This sentiment is worthy of the bumper sticker I saw it on, not serious thinking on a global issue. During the polar vortex of January 2014, I experienced the coldest days of my life, noticeably worse than the winter I spent in Alaska. Thinking that this negates climate change represents the most fundamental misunderstanding of the topic, which is fine. It’s a fair question. It’s refusing to believe the answer that is the problem.
The temperature at one place and time does not address climate, certainly not climate change, and most certainly not global climate change. Inhofe rolling a snowball in D.C. fails to cancel out Greenland’s melting ice sheet or the global temperature average over centuries. Weather is local and fueled by short-term atmospheric and oceanographic conditions. Looking at the long-term, we see that in the 1950s, record highs were recorded 1.09 times for every record low. Fifty years later, there were 2.04 records highs for every record low.
On the issue of climate change, persons outside the field have conflict, while those inside have consensus. Science historian Naomi Oreskes examined 10 years of papers in scientific, peer-reviewed journals and found 980 asserting manmade climate change and zero opposing it. What counts as scientific and peer-reviewed is subject to debate, but even less stringent definitions found just 34 articles arguing against manmade climate change, compared to more than 13,500 reaching the opposite conclusion.
Another line frequently heard is that global warming has peaked. This only works if you start with 1998, which saw record-breaking heat due to an unusually strong El Nino. Choosing any other year as the starting point shows an increase in global temperature. The 10 hottest years on record are all since 1998, with nine of those years since 2002, and 2014 the warmest yet, polar vortex or not.
The 1998 claim requires cherry picking, but a more reasonable objection seems to come from the idea that Antarctic sea ice is increasing. This is true, but Antarctica is also losing land ice. Antarctic land ice is the result of thousands of years of snowfall and is stored ocean water that fell as precipitation. Meanwhile, Antarctic sea ice forms in saltwater primarily during the winter. This is a crucial distinction because when land ice melts and flows into the oceans, global sea levels rise. When sea ice melts, this does not happen.
A common refrain is the trumpeting that scientists once predicted global cooling. This most frequently appears alongside an image of a 1975 Time cover story warning of a coming Ice Age. Rather than showing that scientists are untrustworthy, this demonstrates that they adjust their positions based on evidence. Anyway, there were environmental scientists warning of global warming in the 1970s, and there was not agreement on the issue like there is today.
Then we have the point that Earth was warmer without human influence 6,000 years ago during the Holocene Climatic Optimum. But those higher temperatures were limited to summer months in the northern hemisphere. A more crucial point is that the cause was not CO2 increase, but slow changes in the tilt of Earth’s axis and shape of its orbit.
Similarly, we sometimes hear that current warming is just part of a natural cycle. Never answered, though, is what force of nature is driving this? Which model or theory shows that CO2 does not impact temperature?
Another objection is that the sun is causing the increase, but satellite observations of the sun began in 1978, with no increase ever shown in solar irradiance. MIT atmospheric scientist Richard Lindzen claims climate change is normal, going in 100,000 year patterns. He points out that fossils show alligators once lived in Svalbard, north of the Arctic Circle. However, analysis of the geologic record still shows that greenhouse gasses controlled most ancient climate changes. That’s happening today, on a much grander scale. Besides, the Svalbard alligators fails to address to the central issue of whether deforestation and the burning of fossil fuels is causing the increase in average global temperature.
Back to the point about the consensus among scientists on this issue. The National Academy of Sciences published a study that showed that 98 percent of climate scientists conclude that climate change is human driven. Now, no amount of belief makes anything true, the masses have been wrong before, and we should always be open to new evidence. But if a climate scientist or anyone else has evidence suggesting human activity is not driving the increase in average global temperature, he or she should submit it to Nature, Science, or another highly-respected publication.
Instead, the Heartland Institute buys billboard space to gloat that the Unabomber believes in global warming. Then there’s Dr. Roy Spencer, a University of Alabama professor and former NASA scientist, who has the most polished credentials of anyone taking a contrarian position on global warming. He should be working with peers, sharing data, outlining his methods, experiments, and conclusions, then submitting the findings to Nature or Science. Instead, he declares climate scientists Nazis and emphasizes this by carrying a Swastika flag.