UPDATE: The SREX report is now published in full on the UNFCCC website.

 

As much as climate skeptics would all like us to believe that scientists have been cooking the books to make climate change look worse than it actually is, it turns out quite the opposite is true -- scientists have been downplaying the most extreme impacts. This has been particularly true of the connection between extreme weather and climate change.

 

But now an IPCC (Intergovernmental Panel on Climate Change) report was recently leaked that finally makes a connection most all of us already sense -- extreme weather incidents are on the rise and there is a direct connection to climate change.

 

I was recently on a press call with Weather Underground meteorology director Jeff Masters (who wasn’t involved in the IPCC study) but gave us some of the details. The new correlation found is the unprecedented ratio of "record highs" to "record lows."  Yes there have been extreme droughts, floods, and storm cells going as far back as the 18th century (a point many climate skeptics use to dismiss the theory of global warming), but it's this new ratio between highs and lows that is so unsettling.

 

In the United States this year, blistering heat set 2,703 daily high temperature records, compared with only 300 cold records during that period (a 9:1 ratio) making it the hottest summer in the U.S. since the Dust Bowl of 1936. And by the end of the century, the intense, single-day, heavy rainstorms that now typically happen only once every 20 years are likely to happen every five years.

 

Ever since we have recorded weather data this high/low ratio has hovered around 1:1. Sometimes a little higher or a little lower. Over the past decade however the ratio has shifted to 2:1 worldwide. In 2010 it was about 3:1. This year it is spiking dramatically and factoring in this summer's record heat may be considerably higher than 3:1. Something is clearly wrong, and the only explanation is carbon pollution, aka CO2 emissions from our tailpipes and smokestacks.

 

2011 has brought the costly impact of extreme weather into sharp focus around the world. In the US alone, there have been ten extreme weather events so far, with costs of more than a billion dollars each... more billion-dollar impacts than any other year in history. But this is only a small taste of what is to come. If we continue business-as-usual and rely on fossil fuels to power our economies, extreme weather will become increasingly common, resulting in big hits to public safety and economic stability.

 

It's not surpising then that 285 top-tier investors (representing $20 trillion in assets worldwide) are calling on governments to take immediate action to regulate CO2 emissions. With the UN climate talks coming up in South Africa later this month, there may be yet one more opportunity to make progress towards a fair and binding climate treaty that ensures that investments in clean energy, energy efficiency and conservation will add up to the levels needed to stabilize the climate.