- A Path to Safer Levels of Climate Change

v.1, December 2008
As we already experience problems of changing climate, it is no longer possible to avoid harmful climate change; but by reducing emissions we can reduce the risks of larger climate catastrophes such as large-scale flooding and droughts that deprives larger populations of their homes, livelihoods, or even lives.

Limit Global Warming to 2'C or less.
Most observers that are serious about climate change agree that global climate change must be limited to 2’C or less above the pre-industrial level. The EU countries have agreed to keep global climate change below 2’C. Several environmental NGOs agree that the global temperature should not increase more than 2’C; and then it should soon return to lower levels. New findings of probabilities of higher impacts of climate change indicates that we should aim at a lower limit, such as 1.5’C now supported by the small island states or 1.6 ‘C supported by INFORSE. Even this modest increase could lead to the melting of most of the ice on Greenland, if it is maintained for centuries.

Limit to Atmospheric Concentrations
To limit global man-made climate change, it is necessary to limit the concentration of greenhouse gases in the atmosphere. The concentration of CO2, the main greenhouse gas has increased from a pre-industrial level of 280 ppm to about 385 ppm today and it is increasing 2 ppm/year. While IPCC(www.ipcc.ch) concludes that limit of greenhouse gas emissions to 450 ppm gives a reasonable chance of maintaining the global warming below 2’C, the recent Climate Safety Report finds that we need to return greenhouse gas concentration to close to pre-industrial levels, say 300 ppm CO2. Other studies estimate the safe level of greenhouse gas concentrations between 350 ppm and 400 ppm of CO2-equivalent. The NASA Goddard Institute director Jim Hansen and other "A Path to Safer Levels of Climate Change" (arxiv.org/abs/0804.1126) recommends that we reduce atmospheric CO2 concentrations to 350 ppm at the most after a peak not above 425 ppm.

The science behind these estimates has considerable uncertainties, but that is in no way a reason for inaction, rather the opposite. Two of the major uncertainties are climate sensitivity: how much will the temperature change with a given increase in greenhouse gases, and feed-back, such as the release of the vast carbon stocks in the arctic permafrost areas that is likely to speed up with the melt of the ice on the North Pole. See for instance www.climatesafety.org

If we want to reach greenhouse gas concentrations of 450 ppm, global emissions should peak in 2015 and reduce 85% until 2050, according to IPCC. Others, including INFORSE, have suggested 100% reductions of man-made emissions in 2050, which could lead concentrations of about 400 ppm in the atmosphere. To reach lower concentrations, sharper reductions are necessary, probably combined with active man-made sinks such as large-scale reforestation.

Responsibilities of the Industrialised Countries

The industrialised countries are responsible for most of the emissions, presently and historically. They also have most of the means to invest in the transition. It is therefore reasonable that the industrialised countries take the lead in reductions and also assist developing countries. IPCC has suggested that industrialised countries (Annex 1 countries) reduce from 1990 by 25-40% in 2020 and by 80-95% in 2050 to reach stabilisation of greenhouse gases of 450 ppm. The Greenhouse Development Rights (www.ecoequity.org) group has proposed that industrialised countries take a commitment to reduce by 100% until 2020-2025 (2023 for EU) and then below 0; but that part of the reduction/mitigation is done in developing countries with investments paid by industrialised countries. The actual reductions in industrialised countries could then be about 40% in 2020 and 90% in 2050.

The Greenhouse Development Rights group has suggested reductions of the 27 EU countries, divided in domestic reductions and mitigation in other countries(link). Domestic reductions are 40% in 2020 and almost 70% in 2030. If this is followed by similar sharp reductions in other countries (developing countries emissions peaking 2016-2017), it should give 70-85% certainty that the global average temperature will remain below 2’.

INFORSE proposes a complete transition to efficient use of renewable energy in the EU countries with this achieved between 2030 and 2040 for each of the countries, resulting in no net greenhouse gas emissions from energy supply and use. This requires that no fossil fuel is used and that the renewable energy is used sustain ably and does not lead to net greenhouse gas emissions. As interim targets is proposed for this vision 40% reduction in 2020 and 70% reduction in 2030 with some countries taking the lead and making the full transition until 2030.