Skeptics and deniers can make all the noise they want, but a landmark new report is unequivocal: There is a 95 percent chance that human-generated emissions of carbon dioxide and other greenhouse gases are changing the climate in ways that court disaster.
That's the bottom line from the Intergovernmental Panel on Climate Change, which on Monday released the latest of its comprehensive, every-six-years assessments of the scientific consensus about climate change. According to the IPCC, there is only a 1-in-20 chance that human activity is not causing dangerous warming.
You may like those betting odds. If so, let's get together for a friendly game of poker, and please don't forget to bring cash.
The squawking from naysayers has recently been all about a supposed “pause” in global warming. They say there has been no detectable warming in the past 15 years and claim that any temperature rise that scientists attribute to human activity is really part of some grand natural cycle — probably nothing to worry about, and, in any event, nothing we can control.
One look at the data indicates that the skeptics' view is wishful thinking, at best. It is true that if you look at the period 1998-2013, there is very little warming. But that is because 1998 was an extreme outlier — a sharp spike on the graph. That year was much warmer than the preceding or subsequent few years.
If you plot global temperatures over a longer time period, covering 50 or 100 years, you get a line that jiggles up and down but generally trends upward at an alarming slope. Look closely and you'll notice that 2005 and 2010 were both a bit warmer than 1998.
Why is this happening? Because “the atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years,” according to the executive summary of the 2,000-plus-page IPCC report.