The Gibraltar Magazine

The Weather: A Hot Topic

Not everyone agrees about the extent to which global warming is causing the planet’s climate to change but Jon Lewes looks at the likely impact and how it will affect Gibraltar.

You can accept it, or you can reject it, or perhaps you’ve just been too busy to pay attention to it, yet you should still look for something to do about it, because it may just affect you a lot quicker than you think. Perhaps you feel that Bruce Willis will appear to save us but the reality is that the first truly catastrophic impacts of climate change brought about by ever-accelerating global warming could literally be a decade away, by 2020, and not at the end of the century as some commentators like to tell us. The area in which Gibraltar lies, sandwiched between the continents of Europe and Africa, may be affected twice over, or more.

The UK Met Office’s Hadley Centre says that “the Mediterranean region is one of the sensitive areas on Earth in the context of global climate change due to it’s position at the border of the climatologically- determined Hadley cell and the consequent transitional character between two very different climate regimes in the North and the South.”

The increased risk of inland flash floods and more frequent coastal flooding now being seen in Europe may not be as troublesome for Gibraltar as the problems caused by the rise in sea-levels and drought at the same time. Increases in the frequency of heat extremes, heat-waves and heavy rainfall are very likely and by mid-century many semi-arid areas, including the Mediterranean basin, are projected to suffer a decrease in freshwater resources. Technically, the Gibraltar-end of the Med plays an important role in climate movement because the Mediterranean Sea is a concentration basin with an evaporation rate much larger than the rainfall rate and river runoff, leading to an increase in salt content and it also a acts like a thermodynamic engine which transforms the inflowing light Atlantic water into dense, deep Mediterranean waters through air-sea coupling.

In terms of global mean surface air temperature, the planet has experienced a general warming of 0.6°C over the last century. IPCC estimated changes of the global temperature to be between 2 to 5°C at the end of the 21st century. The global mean temperature is only a mean indicator and changes at regional scales can be much larger. Many global and regional models tend to simulate a warming of several degrees (from 3 to 7°C) on the Mediterranean for the end of the 21st century and the warming in summer is larger than the global average. There is also a general trend of a mean precipitation decrease, ie less rainfall, for the region (especially in summer), due mainly to the northward extension of the descending branch of the subtropical Hadley circulation.

The upcoming problems were spelt out at the UN Climate Change Conference in 2007 and it was stated afterwards that “The United Nations Climate Change Conference, COP13 (Conference of the Parties 13) in Bali on 3-14 December, was vital in the battle to combat global warming. This year’s scientific report from the UN’s Intergovernmental Panel on Climate Change (IPCC) made it clear, beyond doubt, that climate change is a reality and can seriously harm the future development of the world’s economies, societies and eco-systems. Immediate action is needed to prevent the most severe impacts. Since what is happening to the climate is a global issue, tackling climate change and its impacts can only be successfully co-ordinated at international level. The main goal of the Bali conference has been to get negotiations going on a new international climate change agreement”.

The new agreements need to be in place fast before major “tipping-points” are reached. Highlighted items at the conference were the state of the Amazon rainforest which is essentially our planet’s ‘lung’ and is facing threats from both climate change and deforestation which, under current development plans could reduce forest cover by 53% of the original area by 2050; the melting of the Greenland ice-cap and the melting of Siberia’s permafrost covering an area the size of the United States releasing the many millions of tons of methane gas lying trapped under Siberia’s permafrost into the atmosphere and “pushing global temperatures through the roof ”.

UK has pledged to take action, highlighted in November 2007 by John Hirst, Met Office Chief Executive, when he said: “Prime Minister Gordon Brown’s pledge to reduce emissions by 60% by 2050 is welcome news to all of us. The Met Office has provided evidence that climate change is both unavoidable and significant. There is no doubt that we need to take steps to mitigate the established trends and also adapt to impacts that are already inevitable.”

That is a stark statement with which it seems foolish to argue but there are those who still claim that, for example, not all scientists agree with the predictions, or, the earth will handle and adjust to the problems. The real problem is that those commentators, and scientists, who disagree may not be around to find out how mistaken they were because although the earth will adjust to its problems there is no guarantee that the human species will be among those species to survive the adjustment. Already, the assessment to date is that up to 30% of the planet´s species are at increased risk of extinction if global average temperatures exceed 1.5-2.5°C above 1980-1999 levels because a 1°C average increase in the global temperature of the earth is enough to radically change the climate , in different places, in different ways, right across the planet.

One climate prediction model, in 2005, showed that the climate is likely to heat by 4°C, but could heat by as much as 7.5 degrees — much more than the IPCC or Hadley Centre models. By 2050, a target date in many UK and EU plans for emission reductions, the UK average temperature, says the model, will have risen by about 2.4°C — this is greater than the EU target for world temperaturerise, of 2°C. By 2080, average UK temperature, for example, could have risen by 3.8°C , with a possible range from 1.8 to 7.0 Centigrade These are, too say the least, extremely rapid rises, in geological terms. In the recent book by Mark Lynas, Six Degrees, which compiles the research to date carried out by the many different climate study institutions he spells out the impact that each rise of one degree will have on the planet, and its human population.

At 6°C, he states, we get the best idea of what the planet will be like if we turn the geological clock back between 144m and 65m years to the period which ended with the extinction of the dinosaurs. “It is not too difficult,” he says, “to imagine the ultimate nightmare, with ice gone from both poles, with oceanic methane eruptions near large population centres wiping out millions of people, perhaps in days. Buildings are flattened, people are incinerated where they stand, or left blind and deaf by the force of the explosion, with burnt survivors battling over food, wandering far and wide from empty cities, blocked in by flood plains. “Life on Earth ends with apocalyptic storms, flash floods, hydrogen sulphide gas and methane fireballs racing across the globe with power of atom bombs; only fungi survive.”

If that seems a little extreme, let’s look at how he describes what will happen when global temperatures increase by just 2 °C. “Fresh water lost from a third of the world’s surface, low-lying coastlines flooded, Europeans dying of heatstroke, forests ravaged by fire, with a third of all species facing extinction” And at 3 °C, “the runaway thaw of permafrost makes global warming unstoppable, much of Britain is uninhabitable by severe flooding and the Mediterranean region is abandoned.” Before you get out your map to choose a safe place to relocate to, you might like to talk to local environmentalists in Gibraltar, such as GONHS, Friends of the Earth and Helping Hand to tell you about your carbon footprint and how to reduce it. Every little bit will help.