The furore around global climate change is evidenced in daily headlines from around the world. Most notable has been the recent “Climategate” scandal, where private emails were hacked and released to the public. Opponents of the idea of climate change attack the science whenever possible, notably, though, through the mass-media rather than peer-reviewed journals.
Simply put, climate change is the alteration of long-term weather patterns. It is happening now, and all the available science supports the contention that it is primarily human-caused, despite what the deniers may say.
Earth’s atmosphere, weather and climate are like an engine, powered by the sun. Everything is in a delicate balance, with the atmosphere trapping enough heat from the sun to make the planet liveable, but not so much that it becomes unbearable. The most important atmospheric gas in this balancing act is carbon dioxide.
Carbon dioxide is essential for life. Plants use it, and the light from the sun, for photosynthesis, and provide the foundation of the food chain. As mentioned previously, it helps keep the planet warm enough for life. But what happens when there is too much of it? We’re beginning to find out.
Since the start of the industrial revolution in the 1700s, mankind has been releasing carbon dioxide into the atmosphere in ever-increasing amounts. While the planet has the ability to cope with limited increases in carbon through a variety of natural sinks, they are quickly filling up. The oceans, the biggest of the carbon sinks, are starting to undergo acidification due to the immense amounts of carbon they have soaked out of the system. The sinks have limits. And these limits have seen carbon dioxide levels in the Earth’s atmosphere increase by 32% since the factories of the industrial revolution began belching smoke into the sky. This has been measured using ice cores from Arctic and Antarctic glaciers, and from the remnants of other swiftly declining glaciers from all over the globe.
As a result of this increased carbon loading, the average temperature across the globe is increasing. Since 1990, that temperature has risen by 0.6 degrees Celsius, and the northern hemisphere is warmer than it has been in over 1000 years.
Remember that the atmospheric system is an engine, driven by heat from the sun? This extra energy has to go somewhere, and do something. When you add more heat to an engine, it goes faster. There is more mechanical energy. On earth, this mechanical energy translates into wind and weather systems. So with more energy in the system we should expect to see wilder weather and bigger storms.
We have evidence for wilder weather. The winter storms of early 2010 that shut down much of the US eastern seaboard are part of this, as is the unusually energetic hurricane season forecast for 2010. In September, eight named storms formed, tying two prior years for the highest number generated in any month.
Every piece of peer-reviewed science on climate change has supported the contentions that the climate is changing, and that human activities are the root cause. The science backs this up, and even anecdotal observations about weather and temperatures all support the same idea. The climate is changing, altering weather patterns, and human actions are to blame. No amount of dodging the question, or questionable “back-of-the-envelope” calculations can get around the facts. Climate change is real, and it is due to human activity.