Week 3

Week 3: We are changing the climate — Comments and Reflections

The reason why the Arctic is warming faster is generally reckoned to be the sea ice albedo, which was the ‘correct’ answer to course question 5. However, there are news stories this week that researchers with the Max Planck Institute in Germany have found that temperature feedback in the Arctic is causing more warming in that region than sea ice albedo. A cap of cold layered air is hovering over the Arctic, holding in the air. (Reported 3rd Feb on the science website Phys.org.) Science always moves on.

Read the full story at: http://phys.org/news/2014-02-temperature-feedback-magnifying-climate-arctic.html#jCp

My home town in Cornwall has been subject to Met Office severe weather warnings – meaning possible danger to life – twice in recent weeks, though thankfully the flood defences held. When buying a house here, we deliberately chose not to buy one on the riverside, but some way up the hill, to avoid the possibility of flooding. (Even there, when the drains fill or block, I get a 5cm deep flood on my front path. Not a great worry, admittedly, but the layer of mud it deposits is irritating.)

The storms that brought the rain are also battering the sea cliffs and causing collapses, especially where the rain has soaked and weakened the cliffs.

The threats are to low lying homes and industries, where higher sea levels and increasing storm surges will cause more and more regular damage. On that basis, does it make sense to have nuclear power stations on the coast? And if it is too late to move the old ones, does it make sense to build a new one there – Hinkley Point? The Japanese might be able to give us an answer on that.

Longer term, agricultural production will suffer. Farmland under water during the planting season, such as on the Somerset Levels, will not produce much food come the harvest. “Watch the prices go up next summer,” as a farming friend said a couple of days ago.

I’ve done a brief calculation on the amount of CO2 people breathe out. It’s about 1 kilogram per person per day (perhaps a little less). So for 7 billion people that’s 7 billion kg or 7 million tonnes per day. Over a year, that makes 2.5 billion tonnes, or 2.5 petagrams. That carbon is all recycled, coming from food which originated in plants photosynthesising, taking in CO2 from the atmosphere.

Human activity releases 10 petagrams (or 10 billion tonnes) of CO2 into the atmosphere each year, 90% from fossil fuel and 10% from deforestation. So we are putting out roughly four times the amount of CO2 from fossil fuels as from living. No wonder it is building up.

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