WHAT ABOUT THIS WEATHER?
Everyone seems to be talking about the weather as never before.
After 2013 saw the coldest spring in the UK since 1891 and December 2013 was the stormiest since records began in 1869, 2014 opened with the wettest January in southern UK since 1988, and the fifth wettest ever.
The prolonged flooding in the Somerset levels is a visible symbol of the disruption to many peoples’ lives, and has exposed politicians to criticism concerning flood defences. Some have wondered whether the widespread flooding is God’s judgment on the UK (see ‘the commentary’ on page 5).
The UK has experienced three one-in-100 year probability floods in the last ten years. In contrast California is experiencing its most severe drought since records began in1860. It is against this background that the Intergovernmental Panel on Climate Change (IPCC) published its Fifth Assessment report last autumn. The report continues the theme developed in earlier reports that man-made climate change is happening. It asserts that: ‘human influence on the climate system is clear’. The report quotes data showing all the key parameters pointing to climate change and the human input to it.
The average land and ocean surface temperature has continued to rise since 1850. Greenland and Antarctic ice sheets have been losing mass. Glaciers have continued to shrink worldwide and arctic sea ice and northern hemisphere spring snow cover have continued to decrease in extent.
Mean sea level is rising and acidity in the oceans is on the up due to increased absorption of carbon dioxide. It says that this is all a reflection of higher atmospheric concentrations of the main greenhouse gases, carbon dioxide, methane and nitrous oxide which are now at the highest level as measured from ice cores for the last 800,000 years.
Challenging the findings
It has to be said that the IPCC is not without critics and a number of its findings have been challenged. Conspiracy theories abound. For example, R.M. Carter’s Climate Change: the Counter Consensus and Michael Crichton’s popular novel State of Fear both allege that the scientific establishment has distorted data and banded together to create a profitable bandwagon of funding to study climate change.
One of the charges against the IPCC is that it has ignored the cyclical nature of the earth’s climate. This is untrue. Its latest report records the fact that in the early medieval period (950 to 1250) some regions were as warm as the late 20th century but the geographic spread of the warming was not as great as it is now. More scarily, it also notes that between 129000 and 116000 years ago the Earth was 2°C warmer and the mean sea level was 5 to 10 metres higher than it is now.
The strongest challenge to the IPCC has come from the fact that the rate of the earth’s warming has slowed in the period 1998 to 2012 with very little change in temperature in this period. This is discussed in the IPCC report. A number of mechanisms have been suggested including the effect of volcanic eruptions, a redistribution of heat within the oceans and the incidence of a naturally occurring cooling cycle. Although the IPCC admits there is no convincing evidence for any of these influences, as a practising scientist I am not surprised that results occur which are not fully understood.
The earth’s climate system is extremely complex. Surface temperatures vary between –50°C to +50°C. Science has only a broad understanding of what goes on. Surprises often occur. Anomalies happen. Within the IPCC report they acknowledge difference between the Arctic and Antarctic. The arctic sea ice is decreasing markedly in summer while the Antarctic sea ice sheet is on average growing, despite overall loss in Antarctic ice mass. It would be premature on the basis of one set of parameters to believe climate change has gone way.
While not every outcome can be fully explained, some things are obvious. The continued loss of the Arctic ice sheet in summer is easily observed to the extent that articles are appearing discussing the opening of new sea lanes to shorten the freight route between Europe and China and debates are starting about who owns and will police these new links.
No impact on CO2
The distressing thing about the IPCC report is that despite various government actions taken since the Kyoto accords in 1997, no observable impact has been made on the carbon dioxide level in the atmosphere, probably due to the rapid industrialisation in emerging economies. The IPCC report highlights that climate change is still happening. Extreme events such as heat waves and exceptional rainfalls can be expected to increase. Serious impacts can be expected by 2050. The government chief scientist, Sir Mark Walport, recently accused climate sceptics of questioning the scientific evidence in order to dodge the more challenging question of what to do about it (The Times January 27, 2014).
Christians will readily recognise human unwillingness to accept the consequences of mankind’s actions and should be prepared to engage in a debate to preserve the eco-system of our God-given world.