Wacky Weather – The Human Impact on Global Climate

The early weeks of 2011 saw major flooding involving loss of life and significant damage to property in Australia, South Africa, Sri Lanka and Brazil. Each on their own were not unique (although the Brazilian floods were their worst in terms of death toll) but it does seem to be the first time that all have suffered in such a short space of time. Just a few weeks previously, the UK suffered its coldest December since records began prompting many lay people to ask “what happened to global warming?” Well, it is still here and all these wacky weather events are entirely consistent with what climate scientists expect.

Before we look at just how strange the weather is becoming, let’s just remind ourselves of the core elements of the problem. Over one hundred and fifty years ago, scientists discovered that the Earth retained some of the heat from the sun because of the composition of its atmosphere and this was called “the greenhouse effect”. By the end of the 19th century the role of carbon dioxide and its heat absorbing capabilities had been calculated and the first prediction that man’s activities could alter the composition of the atmosphere, and hence the climate, made. By the middle part of the 20th century, scientists had begun to claim that global warming was evident and climate change was underway: the combination of man’s clearance of forests and burning fossil fuels were identified as the culprits. So far, so good: but here is the really interesting bit. In 1988, the UK’s leader Margaret Thatcher, who had studied chemistry at university, was the first major leader to call for action. The following year, the fossil-fuel and other U.S. industries formed the Global Climate Coalition to tell politicians and the public that climate science is too uncertain to justify action. This later line of argument has been easy for the lay public to accept; after all the benefits and convenience of using fossil fuels is enormous. Why would you want to believe they may be dangerous to the future health of the planet? And even if they are, isn’t it going to take so long that it is a problem for future generations to worry about?

Well, let’s just have a look at what has been happening with “global weirding” a fairly appropriate term that started to make an appearance to describe the variety of strange weather events. According to the United Nations Environment Programme (UNEP) there were 63 weather events that set records during the period 2007 to 2009. These were recorded across all continents and included events of apparent heat and cold. For example, in northern Russia, 2008 saw the largest January extend of snow on record but also the fastest thaw with March, April and the boreal spring having the lowest extent on record. A little to the west, the same year saw the warmest recorded winter in most of Norway, Sweden and Finland. To the south, January 2008 saw the heaviest snow in over a decade in Iran and the first snow in living memory in Bagdad, Iraq. That did little to help the drought there, though, and 2009 saw Iraq suffer its fourth consecutive year of drought with half of the normal rainfall leading to the loss of 60% of the wheat harvest. Before the flood conditions of early 2011, Australia had been suffering a decade long drought and 2009 had southern Australia experiencing record high temperatures, which in turn sparked wildfires and loss of life. Deaths were also recorded in the summer of 2009 in India where an intense heat wave sustained temperatures exceeding 40 degree Celsius and provoked at least 100 casualties. The list goes on: on every continent, storms, floods, droughts beyond anything that could be considered “normal”.

Any list of conditions, however, does little to present a coherent case and, intuitively, why does a warming world still experience unusually cold periods in certain places? Weather researcher Andy Russell from Brunel University explains the UK experience of an unusually cold winter as being related to an unusually warm Arctic one (where the extent of sea ice in December was at its lowest since we have been able to measure it from satellites). This has provoked changes to the wind patterns over a region reaching all the way down to Europe. So, whereas the UK winters used to be bathed in relatively warm winds from the west, it is now experiencing bitter winds from the east.

Climate science is complicated and our understanding of it and ability to predict what will happen in the future is still evolving. To some extent, trying to get a good understanding of where the best practice and exemplars are to be found was the motivation behind world government’s setting up the Intergovernmental Panel on Climate Change (IPCC). The IPCC is neither a strictly scientific nor a strictly political body, but a unique hybrid. This was a deliberate political decision and met the divergent needs of a variety of groups and countries. As most of the world’s climate scientists were drawn into the IPCC’s processes, it was intended that it would become a pivotal player in informing policy debates. The panel has reported four times since its inception, the most recent one in 2007. Each report has become surer of the climatic trend towards global warming and man’s activities as being the cause, to the extent that it is now beyond reasonable scientific doubt. Its prognostics for the future have been presented as being a range of possibilities because what will happen in the future will be determined by how we continue in the present. Continue to cut down forests and burn fossil fuels at the current rate of increase and the global average temperature will continue to rise, causing more and more destructive climatic events. Reverse those trends and the worst effects can be avoided.

Global warming is now no longer a technical issue, it is a political issue. Granted it is a very difficult political issue as it involves balancing the desires of those developed countries to carry on with current lifestyles with those of the large developing countries to extend a similar lifestyle to more and more of their populations. But human beings are very resourceful and creative creatures: in many ways it is what defines us. We do have our failings, and one of those is that the majority can’t grasp the significance of climate change because it is too abstract, and not dramatic enough (despite the growing quantity of catastrophe footage), and so don’t put pressure on their politicians to reach a solution. Without sufficient pressure, politicians don’t act.

The unique feature of climate change is that by the time we are experiencing insufferably massive floods, freak weather, sea-level rises and higher temperatures, we will be well past the point of being able to do anything about it. There are solutions to climate change and it is our choice to implement them now or not. Choosing to ignore the evidence and understanding and carrying on with “business as usual” would surely be the greatest global wierding ever.