Scientists have been warning for decades that human caused climate change will bring an increase in extreme weather and it seems that our carbon chickens are now coming home to roost.

Hurricane Sandy was arguably one the most dramatic extreme weather event in 2012 but there was fierce competition for that title as, around the world, extreme weather destroyed communities and devastated lives.

Devastation after hurricane Sandy

This year has barely begun and already we have seen record-breaking heat in Australia, flooding in Africa and Indonesia and drought in India.

So can these events really be directly attributed to climate change?

As the body of evidence grows, the scientific community is increasingly acknowledging the links between current extreme weather and climate change.

The Australian Bureau of Meteorology described this year’s record-smashing heat wave in Australia as consistent with climate change. Speaking about the floods that followed, Professor John Nott told the New Scientist that Australia might be experiencing a "double whammy" of climate change and natural variability, driving wetter conditions.

The most recent study of climate extremes found that record-breaking monthly temperature records are already occurring five times more often than they would without human caused global warming and there is an 80% chance that any monthly heat record today is due to climate change. The authors of the study also suggested that, unless we take steps to significantly reduce human greenhouse gas emissions, by 2040 the frequency of monthly heat records will become 12 times the rate to be expected in a non-warming world and we will be able to blame more than 90% of heat records on global warming.

The UK Met Office recently analysed data from 11,000 precipitation stations around the world, looking specifically at how extreme events have changed between 1901 and 2010. Although there are gaps in the data which means that the coverage is still insufficient to provide a truly global picture of changes, it concluded that in large areas of the world, the number of days with heavy rainfall and the amount of rain that falls during such events have both increased in the last 60 years.

In fact, it is fair to say that all weather events are now affected by climate change, as the environment in which they occur is warmer and moister. As the planet heats, weather patterns are destabilised. Warm air sucks more water from the ground and holds more water, contributing to droughts in some areas and torrential rain in others. Every event has a complex set of causes, but central to these is an increased global average temperature. In that sense there is no longer any such thing as a “natural” (pre-warming) event -- all weather is influenced to some degree.

The disasters the world is experiencing now are happening at a time when the average global temperature has increased by 0.8ºC.  They are just a taste of our future if greenhouse gas emissions continue to balloon.

The fossil fuel industry has always shown scant regard for this unfolding global disaster but is now taking that disregard to a whole new level.  There are plans for 14 new massive coal, oil and gas projects around the world that would produce as much new carbon dioxide (CO2) emissions in 2020 as the entire US, and delay action on climate change for more than a decade. 

Continuing on this pathway will make it difficult, if not impossible, to prevent the widespread and catastrophic impacts of climate change. The costs will be substantial: billions spent to deal with the destruction of extreme weather events, untold human suffering, and the deaths of tens of millions.

The world is clearly at a Point of No Return: either replace coal, oil and gas with renewable energy, or face a future turned upside down by climate change.