February 16, 2009

Urgent need for action on climate change

Filed under: Environment — Tags: , , — 4fooey @ 7:35 pm

The need to do something about climate change is now becoming extremely urgent and is without doubt man’s no. 1 challenge. The  “STERN REVIEW: The Economics of Climate Change” was published in 2006 and it seems very little has been done, apart from that the UK government has passed a law to commit the UK to a cut of greenhouse emissions by 80% by 2050. This is fine in itself, but I wonder how on earth this is going to be achieved — I don’t see the practical steps towards this target being taken. To see how urgent this is, you just need to read the Stern Review again — the following are extracts from the review:

The scientific evidence is now overwhelming: climate change presents very serious global risks, and it demands an urgent global response.

Climate change is global in its causes and consequences, and international collective action will be critical in driving an effective, efficient and equitable response on the scale required.

The benefits of strong, early action on climate change outweigh the costs. What we do in the next 10 or 20 years can have a profound effect on the climate in the second half of this century and in the next.

No-one can predict the consequences of climate change with complete certainty; but we now know enough to understand the risks. Mitigation – taking strong action to reduce emissions – must be viewed as an investment, a cost incurred now and in the coming few decades to avoid the risks of very severe consequences in the future.

The stocks of greenhouse gases in the atmosphere (including carbon dioxide, methane, nitrous oxides and a number of gases that arise from industrial processes) are rising, as a result of human activity. The current level or stock of greenhouse gases in the atmosphere is equivalent to around 430 parts per million (ppm) CO2, compared with only 280ppm before the Industrial Revolution.

Even if the annual flow of emissions did not increase beyond today’s rate, the stock of greenhouse gases in the atmosphere would reach double pre-industrial levels by 2050 – that is 550ppm CO2e – and would continue growing thereafter.

But the annual flow of emissions is accelerating, as fast-growing economies invest in high carbon infrastructure and as demand for energy and transport increases around the world. The level of 550ppm CO2e could be reached as early as 2035. At this level there is at least a 77% chance – and perhaps up to a 99% chance, depending on the climate model used – of a global average temperature rise exceeding 2°C.

Under a BAU scenario [levels of emissions remain the same as today, therefore assumes no accelaration], the stock of greenhouse gases could more than treble by the end of the century, giving at least a 50% risk of exceeding 5°C global average temperature change during the following decades. This would take humans into unknown territory.

The following are possible physical outcomes, taken from the Stern Review, of temperature rises of between 1 to 2°C and 3 to 5°C.

1 to 2°C rise

Food – Falling crop yields in many developing regions, rising number of people at risk from hunger, with severe impacts in marginal Saharel region.
Water – Small mountain glaciers disappear worldwide, significant changes in water availability (e.g. more than a billion people suffer water shortages in the 2080s).
Ecosystems – Coral reefs extensively and irreversibly damaged, large fraction of ecosystems unable to maintain current form.
Weather – Rising intensity of storms, forest fires, droughts, flooding and heat waves.
Risk of rapid climate change and major irreversible impacts – Risk of weakening of natural carbon absorption and possible increasing natural methane releases and weakening of the Atlantic THC, Onset of irreversible melting of the Greenland ice sheet.

3 to 5°C rise

Food – Entire regions experience major declines in crop yields (e.g. up to one third in Africa).
Water – Sea level rise threatens major world cities, including London, Shanghai, New
York, Tokyo and Hong Kong.
Ecosystems – Possible onset of collapse of part or all of Amazonian rainforest, Many species face extinction (20 – 50% in one study).
Risk of rapid climate change and major irreversible impacts – Increasing risk of abrupt, large-scale shifts in the climate system (e.g. collapse of the Atlantic THC and the West Antarctic Ice Sheet)

The most alarming outcome listed above is that for a rise of 5°C, for which Stern says there is now a 50% risk of happening, up to 50% of the earth’s species are at risk of extinction — this prospect is truly appalling and would be catastrophic for life on earth.

In a recent meeting of the American Association for the Advancement of Science (AAAS), Prof James McCarthy said the planet will be in “huge trouble” unless Barack Obama makes strides in tackling climate change. Prof McCarthy said that the US has just four years to save the planet. And at the same meeting, Professor Chris Field, said future temperatures “will be beyond anything” predicted. He said warming is likely to cause more environmental damage than forecast: “We are basically looking now at a future climate that is beyond anything that we’ve considered seriously in climate policy”. He said the increases in carbon dioxide have been caused, principally, by the burning of coal for electric power in India and China. “Without effective action, climate change is going to be larger and more difficult to deal with than we thought,” he said.

The measures now needed to deal with climate change are going to extensive and will effect every area of life — and the changes required need to start in the next months and years. We simply don’t have a moment to lose.


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