How will our climate change?
A gradual increase in temperature along with a change in the pattern of precipitation will bring hotter drier summers and milder wetter winters. There will probably be some shifting of the seasonal weather trends, such as early and late frosts.
There will also be a gradual rise in sea levels - as much as 50cm by the 2080s.
The following Key Findings for the Isle of Wight are taken from the work of the Defra UK Climate Impacts Programme, using the latest figures from UK Climate Projections 2009 (UKCP09). Click here for further details of UKCP09
The predicted figures below (unless otherwise stated) are for the 2020s (2010 to 2039) using a “medium emissions scenario” (i.e. taking predictions for future climate change emissions resulting from population growth, technological changes, economic growth etc). They are all relative to a baseline of 1961 to 1990.
Whatever actions we take now to reduce the effects of climate change are for the more distant future – they will have little or no effect between now and 2030.
Source of graphs below: http://ukcp09.defra.gov.uk/
An increase in 1 or 2 degrees Centigrade may sound small, even pleasant, but average temperatures today are only 5 degrees Centigrade higher than they were at the peak of the last ice age. Increase in average winter temperature is likely to be 1.3 degrees Centigrade in the 2020s increasing for the 2050s to 2.2 degrees Centigrade and for the 2080s to 3.1 degrees Centigrade.
Increase in average summer temperature – the central estimate for the 2020s is 1.6 degrees Centigrade increasing for the 2050s to 2.8 degrees Centigrade and for the 2080s to 3.9 degrees Centigrade.
Winter precipitation will steadily increase, the central estimate for the 2020s is 8% higher increasing for the 2050s to 17% and for the 2080s to 22%.
There is a projected decrease in average summer precipitation – the central estimate for the 2020s is an 8% decrease. The projected central estimate for the 2050s is a decrease of 17% and for the 2080s to 21%.
Sea level along the Hampshire Coast had been predicted to rise at a steady 6mm/yr but is now expected to rise exponentially (4mm/yr until 2025, 8.5mm/yr until 2055, 12mm until 2085 & then15 mm/yr). Sea level rise is now a 'reality' that cannot be stopped in the foreseeable future. Communities need to start thinking now about how they can adapt to sea level rise and its consequences for them over the next decades.
Adding slightly to the effects of sea-level rise on the Island is the fact that land in the South of England is dropping at a rate of about 1mm/year. This is due to the earth’s surface re-adjusting to the melting of the last ice sheets in Northern Europe.
Extreme Weather Events
More dramatic than the gradual effects of Climate Change described above, and probably more disruptive, will be the increase in the number and severity of extreme weather events. These are less easy to predict, but may include droughts, heatwaves, heavy rain and flooding, high winds and storms.
The Pitt Review was written as a reaction to the floods of 2007. It refers to,
“the wettest summer since records began” and the fact that “events of this kind are expected to become more frequent”.
“To put the events into context, there were over 200 major floods worldwide during 2007, affecting 180 million people. The human cost was more than 8,000 deaths and over £40 billion worth of damage. But even against that dramatic back-drop, the floods that devastated England ranked as the most expensive in the world in 2007”.
The Isle of Wight Strategic Flood Risk Assessment shows which areas of the Island are at risk of flooding, the report can be downloaded from the Council’s website (click here to visit the links page).
Examples of extreme weather events which have hit the Island in recent years are included Isle of Wight Extreme Weather Media Study. As one recent example, a Storm Surge occurred on the 10th March 2008 caused by a very deep depression (965mb) together with extremely high winds in the English Channel. The effect on the Island was that Yarmouth Harbour was flooded as the water height reached 1.1m above the predicted high spring tide.