Global Trends by Martin Khor
Monday 7 May 2007
Preventing catastrophic climate change is still possible, but only if the world is willing to undertake drastic economic, technological and lifestyle changes. According to last Friday’s latest climate report, the cost of change will be only 3% of world income.
Climate change is going to have a disastrous effect if the world continues to do “business as usual”, with temperatures rising by 3 to 6 degrees centigrade, and catastrophic results including rising sea levels, melting glaciers, water shortages, floods and decreased agricultural yields.
That’s the bad news in the scenarios revealed by the world’s leading climate scientists in the third and most interesting report of the Inter-governmental Panel on Climate Change (IPCC), released last Friday in Bangkok.
The good news is that steps can be taken to avert the climate chaos at relatively low cost. It would take only 3 per cent of world income in 2030 to carry out the major changes needed. That works out to a reduction in the growth of Gross Domestic Product (GDP) of only 0.12% per year until 2030.
A very small price to pay to keep Earth going, for the sake of humanity’s future. But the changes needed would be revolutionary. It would need changes to energy systems, technology, transport, buildings, industry, agriculture, how we treat forests and seas, and to lifestyles.
The ultimate aim of these changes is to quickly bring down the emissions of Greenhouse gases (the main one being carbon dioxide), which are the causes of rising temperatures.
The IPCC’s report spells out with data, graphs and tables the stark scenarios of what would happen if emissions are not brought down steeply enough.
Greenhouse gas emissions have grown since pre-industrial times, with an increase of 70% between 1970 and 2004. The largest growth has come from the energy supply sector (an increase of 145%), transport (120%), industry (65%) and land use, land use change, and forestry (40%).
With current policies, global Greenhouse gas emissions will continue to grow in the next decades, with carbon dioxide (CO2) emissions from energy use rising by 45 to 110 per cent between 2000 and 2030.
That would be disastrous in the effects it would have on raising temperatures. The present global temperature is already 0.7 degrees above the pre-industrial level.
Many scientists now believe that if the global temperature increases by more than 2 degrees above the pre-industrial level, there would be irreversible climate changes with very adverse effects. With changes above 3 degrees, there would be catastrophic changes.
An interesting table in the IPCC report shows what could happen with different scenarios.
To keep temperatures from rising more than 2-2.4 degrees, the Greenhouse gas concentration in the atmosphere has to be contained to 445-490 parts per million (ppm). And for that to happen, CO2 emissions must be cut by 2050 to 50-80 percent below the year 2000 level. And to keep on track to this time-table, the emissions must peak by 2015.
This is the IPCC’s best scenario, but even then many scientists and environmentalists would claim it is not enough.
In the next scenario, the temperature rise is restricted to 2.4-2.8 degrees, the Greenhouse gas concentration must be contained to 490-535 ppm, and emissions must be cut by 30-60 per cent by 2050.
In the next scenario, the temperature rises by 2.8-3.2 degrees, with gas concentration at 535-590 ppm, and emission changes range from 5% rise to 30% cut.
A worse scenario is where the CO2 emissions rise by 10-60%, causing Greenhouse gas concentration to be 590-710 ppm, with temperatures rising by 3.2 to 4 degrees, resulting in runaway climate chaos.
In the most disastrous scenario, emissions rise by 25 to 140 per cent, the Greenhouse gas concentration rises to 710-1130 ppm, and temperatures rise by 4 to 6.1 degrees. Human life is almost certainly impossible in many parts of the world.
In order to keep to the first and best scenario, the IPCC estimates that 3 percent of the world’s GDP is required to be spent by 2030, not a very large sum compared to how it would prevent damage worth much more.
Changes required to being down Greenhouse gas emissions would include the use of currently available technology:
Some of these proposals are controversial. Environmentalists for example decry the proposed shift to nuclear power, which brings its own massive problems.
The IPCC report also advocates changes in lifestyle and behaviour patterns so that resource conservation is emphasized. This will contribute to developing a low-carbon economy.
For example, changes in occupant behaviour, cultural patterns and consumer choice and use of technologies can result in considerable reduction in CO2 emissions related to energy use in buildings
The IPCC report will spark much debate. From this, the world may decide to take action, or only half action that is not enough. But the fight over climate will now pre-occupy policy makers and public alike.