Climate change does not equal global warming
I was recently asked why there was a conference taking place in Denmark about Global Warming. This is a question that pains me every time that I hear it – and emphasises the requirement to communicate the message about climatic change!
Climate change does not = global warming.
The headlines of newspapers relating to temperature changes – often quote the range of 1.1.to 6.4degC temperature increases by 2100 sourced from the IPCC. The Press rarely delve to the level of detail below the headlines to explain how this average change is manifest across different geographical regions. This point was further highlighted yesterday during a talk with Pen Hadow who, as part of ClimateWise week, was addressing a Lloyd’s audience about his recent findings with the Catlin Arctic Survey.
Surface air temperatures here in the northern hemisphere are distinctly higher than the reference 1961-90 period. Indeed, the annual mean Arctic temperature for the year 2008 was the fourth warmest year for land areas since 1990. These changing temperature regimes are resulting in a marked decrease in the level of sea-ice thickness in this area.
In the early part of this decade, there were suggestions that the summer sea-ice extent in the Arctic may disappear by the end of the 21st century – it now appears that there may be no summer sea-ice within a decade. The rate of warming here is alarming.
Whilst we are witnessing decreasing sea-ice in the northern hemisphere, we are observing some distinct differences in Antarctica. The British Antarctic Survey recently published the first comprehensive review of the state of Antarctica’s climate. Since 1980 there has been a 10% increase in Antarctic sea-ice extent, particularly in the Ross Sea region, as a result of the stronger winds around the continent (due to the ozone hole). In contrast, regional sea-ice has decreased west of the Antarctic Peninsula due to changes in local atmospheric circulation and this has also been linked with the very rapid warming seen over land on the west coast of the Peninsula.
The picture is confused? Or is it? Regional climate change impacts will be varied – we know this – but does the wider public? On a relatively local scale, the UK Climate Impacts Programme (UKCIP) published a set of probabilistic scenarios for changes in projected UK climate – with distinct regional differences.
On a global scale all of these changes will be further magnified. BUT, this is not what is reported in the press – and does not help to inform the public debate. The impacts of climate change will not necessarily result in uniform warming across the entire planet. This has to be recognised as part of the outcome from COP15. Today is the last day of negotiations in Copenhagen. We await with baited breath as to what the outcome(s) will be. Fingers crossed for a number of positive steps forward.
My other pleas:
1. Better communication around the regional dimension of climate changes, and that the planet will experience different changes as we go forward
2. Improved information around the rate of some of these changes - notably in the Arctic