First, a 12-month running mean of global surface temperature anomalies since 1980 (i.e. for each month, an average is taken of the previous 12-month period – ‘calendar year’ is irrelevant):
The global temperature data can be smoothed by taking an 11-year running mean (which tends to average out ENSO and solar cycles). It shows a 0.2C rise over the last decade, and is now at record levels:
A further smoothing, by taking a 22-year running mean, shows how steady the rise has been in the last few decades, when averaged over a climatically relevant period:
Most additional trapped heat is going into the oceans and land-based ice sheets. As such, sea level rise is a useful ‘composite’ measure of the planetary energy imbalance:
Along with ocean heat content:
The volume of the floating Arctic ice cap shows an ongoing decline:
As is the ice mass sitting on Greenland (and Antarctica):
Global carbon dioxide emissions from fossil fuels are accelerating, with coal making a resurgence:
Last year (2010) broke the record for emissions, reaching rising almost 6% to 30.6 billion tonnes of CO2-e. As the next diagram illustrates, coal and gas are still the backbone of electricity generation for most of the large greenhouse gas emitters:
We are now well and truly heading for the red zone in this forecast:
What does this mean? I’ll let Professor Hans Joachim Schellnhuber of the Potsdam Institute for Climate Impact Research explain:
People often say, well, I have fluctuations of temperatures between say Queensland and Melbourne and whatever, much higher levels – why should we care about it?
You have to compare it to body temperature. Our body temperature is about 37 degrees. If you increase it by two degrees, 39, you have fever. If you have add four degrees, it is 41 – you are dead, more or less.
And you have to think about the body temperature of our planet, which has been brought about through many, many processes over many, many millions of years. So, disturbing our planet at such an amount would, as I said before, create a different world, it would mean agriculture would have to find completely new ways.
And, by the way, Australia is surrounded by oceans – four degrees sustained for a while would mean at least seven or 10 metre sea level rise; probably it would melt down all the ice on this planet. That accounts to 70 metres, seven oh, metres in the long term.