Last time in this continuing series exploring the truth about global warming I talked about the “Ten Key Indicators that Make it Clear – The Planet is Warming.” These empirical data were highlighted in a recently released NOAA report called State of the Climate in 2009. Following that report a physicist by the name of John Cook posted an article called “10 Indicators of a Human Fingerprint on Climate Change” on his highly regarded site “Skeptical Science.” In other words, we know that there is overwhelming empirical evidence demonstrating that the planet is warming, but why are we so sure that it is largely due to human activity? Cook highlights the “many different observations find a distinct human fingerprint on climate change.”
See graphic here.
Cook goes on to link to specific published literature that support each of these indicators of a human fingerprint. I won’t repeat them here but highly encourage readers to go to the Skeptical Science site and review each of the links. Keep in mind that he links to one or a few papers or abstracts that highlight the state of the knowledge…there are many more papers that also contribute to our understanding. The sum total of all of the research in each of these areas is what leads to the overwhelming empirical evidence that human activity – most notably greenhouse gas emissions – is leading to the irrefutable warming that we continue to observe.
The logic behind greenhouse gas emissions causing the warming is sound, as is the basic physics that our observations bear out. Trillions of tons of carbon have been sequestered in fossil fuels for millennia. We are now extracting that carbon and “emitting around 30 billion tonnes of CO2 into the atmosphere every year.” So in a very short period of time we are taking all that carbon built up over millions of years and putting it all back into the atmosphere. Basic physics tells us that the very small amounts of CO2 and other greenhouse gases in the atmosphere are responsible for all of the natural greenhouse effect that makes our planet livable. So doubling the amount of CO2 in the atmosphere is obviously going to throw off the natural balance.
The massive amount of empirical data overwhelmingly demonstrate that the planet is warming. And the massive amount of empirical data overwhelmingly point to human activity, especially CO2 emissions, as the reason for it.
Next time I’ll talk more about the why we know the CO2 building up in the atmosphere comes primarily from fossil fuel emissions and not other sources.See more about climate here.