Climate change is even more urgent then we thought
For over two decades the International Panel on Climate Change (IPCC) has stated in her reports that global emissions should be reduced by 42to 57 % in 2050. This means developed countries should reduce their CO2-emissions by 80% in 2050.
This would give developing countries enough time to reduce their emissions later on, resulting in a 100% reduction worldwide in the year 2100. As a result, CO2 levels in the atmosphere could be stabilized at 450 ppm (parts per million). This in turn would result in a chance of 50% that global temperature increase in this century would not exceed 2 degrees Celcius (3,6 degrees Fahrenheit).
For decades conventional wisdom has been, that the most catastrophic effects of climate change can be avoided if we limit temperatures at this level. All official targets for CO2 reduction aim at that. Right now the world is not on course to reach this goal. Rather, CO2 emissions are still increasing. That’s why our responsible politicians organize climate conferences, making feeble attempts to reduce emissions just sufficiently to have a 50% chance we can reach the 2 degrees target.
It is widely accepted that stabilizing the temperature at lower temperatures would be very desirable. Even if you look at it in terms of costs only. However, in the course of a negotiating process, even the minimal targets easily start to be perceived as something you can compromise on. After all, a watered down agreement is better then no agreement at all. Plus, we need to sell this agreement at home.
However there are a few essential bits of information which make the whole picture look even more alarming:
1: even according to the conventional projections, if we can stabilize CO2 emissions at 400 ppm we would still have a 20% chance on more then 2 degrees temperature rise.
2: Right now, temperatures have already risen with 0,8 % since 1750. A rise to 1,4% by 2050 is already unavoidable because of our current emissions. This is due to the fact that the effects of current CO2 levels on global temperature have a delay of 30-35 years. So right now, we are experiencing only the result of our emissions until 1980! Limiting emissions to a level which would theoretically result in a 1 degree rise (which would actually give a 20% chance on a plus 2 degrees rise) is already not possible anymore!
3: A big problem with CO2 is that it stays in the atmosphere for a long time. According to the IPCC, some 50% will be removed after 30 years, another 30% in a few hundred of years. The remaining 20% will stay for thousands of years. Due to this, if we stop emitting CO2 in the atmosphere, after some time CO2 levels would start to go down. Other scientists see this conclusion as too optimistic. According to them, more CO2 would remain in the atmosphere for a longer time. This means that even if we stop increasing CO2 levels, temperatures will continue to rise several decades and after that they will essentially stay the same. Therefore we should aim at 100% CO2 reduction rather then 80%. We should define how much of our fossil fuels have to remain in the ground and take this as a hard limit.
4: More and more scientists are coming to the conclusion that the reports of the IPCC do not take into account certain ‘positive feedback mechanism’. The word ‘positive’ here does not mean desirable at all. It means that as soon as temperatures rise, this sets in motion mechanisms, which will produce even more greenhouse emissions. One example of these are methane emissions from the arctic. If the frozen soils in Siberia and Northern Canada start to melt, methane which has been stored for many thousands of years will be released into the atmosphere. Another concern is that if ocean temperatures rise, this diminishes the ability to store CO2. Scientists like Kevin Anderson from Tyndall Centre for Climate Research are therefore convinced that we need to stabilize CO2 levels at much lower levels than 450 ppm to have a 50% chance of remaining at the ‘safe’ side of ‘only’ 2 degrees temperature rise. The climate website 350.org derives its name from this – the number refers to the amount of ppm at which we should eventually stabilize CO2 levels.
5: It is also important to point out that temperature rise is not necessarily gradual. As soon as certain ‘tipping points’ are reached, climate change itself will produce more climate change. This is called the ‘runaway greenhouse effect’. A temperature rise of above 2 degrees is regarded as a level at which these tipping points are likely to occur.
6: Even if we can avoid reaching these tipping points, climate change will already have very serious adverse effects. In fact, these are already happening now. Hurricanes and floodings are increasing. More and more people are suffering from heat disease. According to one report, due to climate change annual yearly mortality has already increased with 400.000 persons a year. While for most of these people, global warming is not the only cause of their death (many of them would have died from other causes soon after) the World Health Organization (WHO) estimates that since 1980, 160.000 people have died whose death can directly be attributed to climate change. This is still a lot more then…. (everybody can fill this in for themselves….)
7: The limited climate change we experience now is already causing problems for our agriculture. This is to some extent caused by temperature increase itself, but is mainly due to change in rain patterns caused by climate change. Many fertile agricultural areas are becoming dryer, while in other areas there can be problems due to excessive rain, storms and floods. All of these problems can multiply when climate change becomes more severe. In moderate temperature regions, initially there can be some minor advantages to agriculture, but these will be nullified when temperatures increase further.
8: These problems will occur in a time agricultural production needs to increase due to rising population, as well as increased meat consumption. On top of that, unsustainable agricultural practices are already causing a lot of problems: poisening, damage to the quality of our soils, diminish groundwater supplies and loss of biodiversity (for example, bees!).
9: In relation to this, there is another set of ‘positive feedback mechanisms’ and strengthening effects. If climate change causes food shortages, humanity might try to boost agricultural production in unsustainable ways, using more fossil fuels and cutting down more rainforests – which would of course heat up the planet even further. If the melting of glaciers causes rivers to dry up, farmers will use up groundwater supplies even faster. Or desalinate seawater with the help of fossil fuels, worsening the climate change.
In order to avoid falling into complete despair and apathy when reading this, it is important to realize that there could also be ‘negative feedback mechanism’ which are desirable – they might mitigate the destructive processes. However, in my opinion, all the above information together makes it very foolish to expect we are safe with the official target of 80% reduction in 2050 (in the developed countries). There are much safer routes to a climate friendly economy which aim at stabilization of CO2 levels at 350 ppm. The most radical of these is presented by the earlier mentioned Tyndall Centre for Climate Research. It would require CO2 emissions to drop by 8-10% a year in developed countries. According to economists, 3-4% reduction a year is compatible with economic growth. In the Netherlands, climate organization Urgenda published a plan to reduce CO2 levels with 100% by 2030 – 6-7% a year over a period of time of 15 years. According to their calculations, this would be more cost effective (even from a narrow economic perspective) then a business as usual scenario (which is going to cost us a lot more later on, anyway!!!).
1: The overwhelming majority of climate scientists (97%) support the findings of the IPCC on climate change (IPCC is the International Panel on Climate Change, a scientific organization under auspices of the United Nations)
2: the world is not on course to cut CO2-emissions fast enough to meet the minimum targets set by the IPCC
3: Even if these minimum targets where reached, according to the IPCC, we have only 50% chance to limit global temperature rise to 2 degrees celcius
4: According to the IPCC, if temperatures rise above 2 degrees, there is an increased chance a tipping point would be reached which would make climate change uncontrollable. This means the climate change itself would cause more climate change, causing what is called a ‘runaway greenhouse effect’.
5: Still according to IPCC, even if we could stabilize CO2 emissions at a level which would most likely cause only 1 degree temperature rise, there is still a 20% chance temperatures would rise above 2 degrees.
6: According to some scientists, the projections of the IPCC are still too optimistic. This means we have to cut CO2 levels still faster. In order to limit temperature rise to 2 degrees (which actually means, 50% chance on more then 2 degrees), our carbon budget (the maximum amount of carbon we may still use to attain this goal) is what we will spent in 25 years if CO2 emissions stay the same.
7: Even if we can avoid tipping points which will make climate change uncontrollable, climate change will still have very serious effects.
Hierbij een korte samenvatting:
1: Een overweldigende meerderheid van klimaatwetenschappers (97%) onderschrijft de conclusies van de IPCC-rapporten over klimaatverandering (IPCC staat voor International Panel on Climate Change, een wetenschappelijke organisatie onder auspiciën van de Verenigde Naties.
2: De wereld is ligt niet op koers om de minimum-doelen voor CO2-reductie te halen die door het IPCC worden aanbevolen.
3: Zelfs indien deze minimum-doelen wel gehaald zouden worden, hebben we (volgens de IPCC) slechts 50% kans dat de wereldwijde temperatuurstijging deze eeuw beneden de 2 graden celcius blijft.
4: Volgens het IPCC lopen we bij een temperatuurstijging van boven de 2 graden het risico dat een ‘tipping point’zal worden bereikt die de temperatuurstijging oncontroleerbaar maakt. Dit betekent, kort gezegd, dat de temperatuurstijging zelf nog meer temperatuurstijging zal veroorzaken. Wetenschappers noemen dit een ‘runaway greenhouse effect’.
5: Nog steeds volgens het IPCC; zelfs als we onze CO2 uitstoot beperken met een snelheid waardoor de temperatuurstijging waarschijnlijk beperkt blijft tot 1 graad, dan is er nog steeds 20% kans dat de werkelijke temperatuurstijging meer dan 2 graden zal zijn.
6: volgens sommige wetenschappers zijn de bevindingen van het IPCC nog steeds te optimistisch. Dit betekent dat we onze CO2 uitstoot nog sneller moeten terugbrengen. Om de temperatuurstijging te beperken tot 2 graden (wat dus in feite betekent, 50% kans dat het meer dan 2 graden wordt), mogen we maximaal nog een hoeveelheid CO2 uitstoten die we in het huidige tempo in 25 jaar opgebruiken.
7: zelfs wanneer we weten te voorkomen dat we de tipping points bereiken waardoor klimaatverandering oncontroleerbaar wordt, dan zullen de gevolgen van klimaatverandering nog steeds zeer ernstig zijn.