I was reading a thing on the BBC site about a climate change sceptics meeting in the US. Quite a funny article (they were only serving Beef at the lunch and shunning vegetarians!), but they were talking about the Hockey Stick graph, which was the famous one used by Al Gore in his film An Inconvenient Truth.
It basically shows a fairly flat line to the middle and left (the ‘stick’) and then a sharp rise to the right (the ‘head’). Some of the people interviewed for the article were saying that this representation has now been disproved, meaning that the warming we’re experiencing now is comparative to other periods in the last few hundred years, therefore it’s not humans affecting this rise.
Well, there is still a lot of evidence to support the theory that there is a sharp increase caused by human activity. The 10 or so independent reports shown in the graph used tree rings, historical records, corals, ice cores, lake and ocean sediments, boreholes, glacier length records and direct instrumental records.
The direct records match very closely the data from other sources and the consensus is that other ways of gathering data is a sound method for establishing past temperatures and CO2 levels.
It’s not like 1 person has published a paper based on a random set of data and then every government has based their entire climate policies on that. The graphs show strong correlations between 10 sets of data, which use all the different data sources listed above.
The main thing which comes across is the speed at which change is occurring. Yes, there have been hotter periods in earth’s history and also much colder ones (if you go back tens of thousands or millions of years), but changes have occurred much more slowly in the past. All the lines are moving in the same pattern and in the same direction.
If there was significant and credible evidence to suggest otherwise, I would use that, but there isn’t.
We can wait another 20 years to get even more data to base policies on, before we do anything about it, but that would quite frankly be stupid and highly irresponsible. There is just too much riding on this issue.