In October 2007, Lord Monckton of Brenchley published a response to Al Gore’s book and movie “An Inconvenient Truth”. In it Lord Monckton cites 35 errors in the movie. This came on top of a British judge decreeing that the film contained nine errors that needed to be clearly explained if it was to be used as a teaching aid in schools in the UK. Importantly the judge also said that, “Al Gore’s presentation of the causes and likely effects of climate change in the film was broadly accurate”.
The science behind climate change is complicated but the consensus amongst climate scientists is that it is a serious, man-made problem. Al Gore is not a climate scientist, Lord Monckton is not a climate scientist (he has a classics degree) and I am certainly not a climate scientist, but there are specialists out there who can support their claims that man-made (anthropogenic) global warming (AGW) is happening. With the help of the Internet I am going to try to identify how many of Lord Monckton’s 35 claims are supported by the scientific community.
1 Sea level “rising 6m”
This is too high a figure from current projections. There are various different ways of projecting sea level rise and there are a huge number of variables to be taken into account. The melting of the Greenland and Antarctic ice is one factor as is the expansion of the oceans as a result of higher temperatures. The Intergovernmental Panel on Climate Change (IPCC) estimates a rise of between 20cm to 80cm by 2100. Combining the most recent data leads to an estimate of between 80cm and 2m. Nothing like the 6m Al Gore suggests but still enough to flood Holland, Florida and London.
2 Pacific islands “drowning”
Low lying Pacific islands will be affected by sea level rise as their groundwater becomes brackish and their coasts are eroded. “Unlike New Zealand, which in 2001 began accepting 75 Tuvaluans a year, Australia has so far not acknowledged the prospect of climate refugees.” – TheAge.com.au Although the islands have not been evacuated yet as implied by the film, there are measures in place in case the problem becomes severe.
3 Thermohaline circulation “stopping”
Large volumes of fresh water entering the North Atlantic from ice melting, may have an effect upon the Gulf Stream that brings warm water up to Europe from the tropics. It is unlikely to cause an ice-age in Europe but it is nonetheless potentially worrying. As this paper in Nature explains, we do not have enough data to accurately model the potential outcome but it is now an active area of research.
4 CO2 “driving temperature”
In the past, CO2 increases in the atmosphere have lagged behind increases in temperature caused by changes in solar output and shifts in our orbit of the sun. The relationship is complex but as the oceans increase in temperature, CO2 is released, and this causes further increases in temperature. So rising CO2 levels have been both the cause and the effect of global warming. In the current scenario we can see that CO2 in the atmosphere as a result of burning fossil fuels (and enhanced by reductions in rainforest) are forcing the temperature rise and feeding back to produce more CO2 production and CH4 (methane) release from previously frozen tundra. Lord Monckton dismisses the “hockey stick” graph as being “now-discredited”. This is not the case. Certain data used in the original graph were deemed to be unsafe but the graph has been supported by further research since. I wrote about it a few months ago after a heated discussion with Mr Walker in Blackhole!
5 Snows of Kilimanjaro “melting”
Al Gore seems to be right about this one although global warming is not the only potential cause. It is certainly what we would expect to see and is consistent with the behaviour of other tropical glaciers. The specific debate over Kilimanjaro is whether the disappearance of the ice is due to reduced snow fall or melting (ablation). Even if it is due to reduced snowfall over the last century then this too could be a result of global warming. Mostly, global warming seems to have produced increased snowfall as higher rates of evaporation load the clouds up with water, but this reduced rate of precipitation may be the indirect effect of sea temperature on atmospheric circulation.
6 Lake Chad “drying up”
Gore uses Lake Chad to illustrate that there will be droughts in some areas even whilst there are floods in others. There are multiple causes for the drying up of Lake Chad and reduced rainfall as a direct or indirect effect of global warming is just one. There is plenty of robust research to suggest that Lord Monckton is wrong when he says that “the scientific consensus” does not include global warming as a possible reason for Lake Chad drying up.
7 Hurricane Katrina “manmade”
Hurricanes happen all the time and no one event can be blamed upon global warming. As I understand it, at no point in the film does Al Gore say that Hurricane Katrina was caused by global warming. If that is the case then Lord Monckton is offering a straw man argument. A view widely held is that, with more energy in the form of heat in the atmosphere and oceans, we may see more hurricanes or fewer-but-stronger hurricanes. This is an issue of genuine debate amongst the experts with neither side having the upper hand as yet.
That is enough for now! Seven arguments down and only 28 to go. I will leave you with a video from the excellent PotHoler54 – who is a YouTuber with a great collection of science videos, particularly those addressing climate change.
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