Climate change is one of the defining challenges of the 21st century, along with global population, poverty alleviation, environmental degradation and global security. The problem is that ‘climate change’ is no longer just a scientific concern, but encompasses economics, sociology, geopolitics, national and local politics, law, and health just to name a few. But with so many other problems in the world should we care about climate change? What we are finding is that if we do not produce win-win solutions then climate change will make all our other problems worse.
Human induced Climate Change
We have strong evidence that we have been changing the greenhouse gas content of the atmosphere. The first direct measurements of atmospheric CO2 concentrations started in 1958 at an altitude of about 4,000 metres on the summit of Mauna Loa in Hawaii, a remote site free from local pollution. To extend this record further back air bubbles trapped in ice have been analysed from both the Greenland and Antarctic ice sheets. These long ice core record suggest pre-industrial CO2 concentrations were about 280 parts per million by volume (ppmv). In the 1958 concentration was already 316 ppmv, and has climbed each and every year to reach over 396 ppmv by August 2012. We have caused more pollution in one century than occurred in thousands through the natural waxing and waning of the great ice ages. Interestingly this increase in carbon dioxide in the atmosphere represents only half of the pollution we currently generate. About a quarter is absorbed by the oceans and another quarter by the land biosphere. One of the great worries scientists have is that this natural service may reduce in the future making the situation worse.
According to the IPCC science report in 2007 increases in all Greenhouse gases over the last 150 years has already significantly changed climate including; an average rise of global temperatures of 0.75°C, a sea level rise of over 22 cm, a significant shift in the seasonality and intensity of precipitation, changing weather patterns, and significant retreat of Arctic sea ice and nearly all continental glaciers. According to NASA, NOAA, the UK Met Office and the Japanese Meteorological Agency in the last 150 years the last decade has been the warmest on record (see Figure 1). The IPCC in 2007 stated that the evidence for climate change is unequivocal and there is very high confidence that this is due human activity. This view is supported by a vast array of learned organisations, including the Royal Society and American Association for the Advancement of Science.
Weight of Evidence
Understanding future climate change is about understanding how science works and the principle of the ‘weight of evidence’. Science moves forward by using detailed observation and experimentation to constantly test ideas and theories. Over the last 30 years the theory of climate change must have been one of the most comprehensively tested ideas in science. First as described above we have tracked the rise in greenhouse gases in the atmosphere. Second we know from laboratory and atmospheric measurements that these gases do indeed absorb heat. Third we have tracked significant changes in global temperatures and sea level rise over the last century. Fourth we have analyzed physical changes in the Earth system related to climate including retreating sea ice around the Arctic and Antarctica, retreating mountain glaciers on all continents, and shrinking of the area covered by permafrost and increase depth of its active layer. The ice cover records from the Tornio River in Finland, compiled since 1693, show that the spring thaw of the frozen river now occurs a month earlier.
Fifth, we have tracked weather records and seen significant shifts. In recent years massive storms and subsequent floods have hit China, Italy, England, Korea, Bangladesh, Venezuela, Pakistan, Australia and Mozambique. These observation are supported by detailed compilation of all precipitation record for the Northern Hemisphere published in Nature in 2011 by Dr Seung-Ki Min and his colleagues in Canada showed that there had been a significant increase in the intensity of rainfall over the last 60 years. Moreover, in Britain the winter of 2000/1 was the wettest six months since records began in the 18th century, August 2008 was the wettest August on record and April-June 2012 was the wettest spring on record. Also using data collected by the great British public shows that birds are nesting 12±4 days earlier than 35 years previously. Sixth we have analyzed the effects of natural changes on climate including sun spots and volcanic eruptions and these are essential to understand the pattern of temperature changes over the last 150 years but they can not explain the overall warming trend. And lastly we understand longer term past climate changes and the role greenhouse gases have played in setting the climate of our Planet.
Despite all the evidence, future climate change evokes strong reactions. In part because many of the changes we might have to make seem to go against the current neo-liberal market driven approach in the West. It is also due to a fundamental misunderstanding of science by the media, public and our politicians. This is beautifully discussed in Mark Henderson’s book the ‘Geek Manifesto’. Climategate and the other supposed climate change cover-ups reported in the media are excellent examples of this misunderstanding. Because science is not a belief system, you cannot decide you believe in antibiotics (as they may save your life) and metal tubes with sticky out bits can fly you across the Atlantic Ocean but at the same time deny smoking can causes cancer, or HIV causes AIDS or greenhouse gases cause global warming. This is because science is a self-correcting rational methodology based on collecting and building up evidence, which is at the very foundation of our society. In the case of ‘Climategate’ there was in November 2009 an illegal release, due to hacking, of thousands of emails and other documents from the University of East Anglia’s (UEA) Climatic Research Unit (CRU).
Allegations were made that the emails revealed misconduct within the climate science community including with holding scientific information, preventing papers being published, deleting raw data, and manipulated data to make the case for global warming appear stronger than it is. Three independent inquiries concluded that there was no evidence of scientific malpractice. But what all the media commentators missed at the time is that two other major groups at NOAA and NASA had used different raw data sets and different statistical approaches and published the very same conclusions as the UEA group. Figure 2 shows all of these composite data sets for global temperature over the last 2000 years, and not surprisingly they are different but they show very similar trends and all suggest that the 20th century was warmer than any other time in the last two millennium.
There was also criticism that the UEA group and by extension other climate scientist had changed the raw data. Short hand terminology used by scientist such as ‘correct’, ‘tweak’, ‘manipulate’, ‘a line’, ‘correlate’ of course did not help this very. However, some raw data does need to be processed so it can be compared with other data particularly if you are trying to make long records of temperature when the methods used to measure temperature have changed. The clearest example of this is the measurement of sea temperature, which up to 1941 was made in seawater hoisted on deck in a bucket. Originally these buckets were wooden then between 1856 and 1910 there was a shift to canvas buckets, which changes the amount of cooling caused by evaporation as the water is being hoisted on deck. In addition, through this period there was a gradual shift from sailing ships to steamships, which altered the height of the ship decks and the speed of the ships, both of which can affect the evaporative cooling of the buckets. Since 1941, most sea temperature measurements have been made at the ships’ engine water intakes again another shift. If scientist just stuck all this raw data together it would of course be wrong. Moreover in this case because the earlier sea surface temperature measurements are too cold without correction it would make global warming in the ocean appear much bigger than it really was. So the constant checking and correcting of data is extremely important in all parts of science. But the most important part is can the results be reproduced, is there the weight of evidence from many research groups showing the change. This is why after over 30 years of intensive research into climate change most scientists have a very high level of confidence that it is happening and it is due human activity.
Climate Change and its impact
The IPCC in 2007 reported that global mean surface temperature could rise by between 1.1°C and 6.4°C by 2100, with best estimates being 1.8˚C to 4˚C. The biggest influence on how warm the climate becomes is which emission scenario is used. The faster and higher greenhouse gas emissions rise the hot the World will become. However, it should be noted that global carbon dioxide emissions despite the global recession are rising as fast than the most dire ‘business as usual’ IPCC emission scenarios. The models also predict an increase in global mean sea level of between 18 cm and 59 cm. If the contribution from the melting of Greenland and Antarctica is included then this range increases to between 28 to 79 cm by 2100. All such predictions assume a continued linear response between global temperatures and ice sheet loss. This is unlikely, and sea level rise could thus be much higher. The next IPCC Science report will be published later this year (2013) and will use more realistic future emission pathways, but draft chapters of this report show that they will reach very similar conclusions to the 2007 Report. The impacts of climate change will increase significantly as the temperature of the planet rises. The return period and severity of floods, droughts, heat waves and storms will increase. Coastal cities and towns will be especially vulnerable as sea level rise will increase the affects of floods and storm surges.
A recent multi-disciplinary study by University College London published by the Lancet in 2009 demonstrated the greatest threat of climate change to human health was from reduced water- and food-security, which could affect billions of people. Climate change also threatens the World’s already devastated biodiversity. Ecosystems are already being hugely degraded by habitat loss, urbanization, pollution, and hunting. The 2007 Millenium Ecosystem Assessment report suggested that three known species were becoming extinct each hour, whilst the 2008 Living Planet Index suggested that the global biodiversity of vertebrates had fallen by over a third in just 35 years, an extinction rate now 10,000 times faster than any observed in the fossil record. The Royal Society’s excellent 2012 report ‘People and the Planet’ summarized the huge effects humanity are having on the environment and how this would get worse as global population increases but more importantly as consumption continues to rise uncontrollably around the World. Climate change of course will exacerbate all of this environmental degradation.
What is safe level of Climate Change?
So what level of climate change could be considered ‘safe’? In February 2005 the British Government convened an international science meeting at Exeter, UK to discuss this very topic. This was so Tony Blair, the then Prime Minister would have a political number to take to the G8 conference, which the UK was hosting later that year. Their recommendation was that global warming must be limited to a maximum of 2˚C above pre-industrial average temperature. Below this threshold it seems that there were both winners and losers due to regional climate change, but above this figure everyone seems to loose. This however is just a political number because if you live on any of the low lie Pacific Islands then your whole island may have been flooded by the time we reach 2˚C. However with the failure to produce a new climate treaty it now seems likely that temperature rise will exceed this threshold. At the moment in the ‘business as usual’ emission scenario we hit 2˚C long before 2050, which is not surprising given the International Energy Authority prediction of use of fossil fuels over the next 20 years include a 30% increase in oil, 50% in increase in coal and 40% increase in natural gas.
So what is the cost of saving the world? According to UK Government commissioned Stern Review on The Economics of Climate Change in 2006 (Stern, 2007), if we do everything we can now and reduce global greenhouse gas emissions and ensure we adapt to the coming affects of climate change it will only cost us 1% of World GDP every year. However, if we do nothing then the impacts of climate change could cost between 5 and 20% of World GDP every year. These figures have been disputed. Some experts have argued the cost of converting the global economy to low carbon could cost more than 1% GDP because global emission have risen faster than the worst predictions. In response Sir Nicolas Stern has recently revised his figure to 2% World GDP. Others argue that the costs could be offset by regional carbon trading systems. Others suggest that the impacts and the associated costs of global warming have been under-estimated by IPCC and the Stern Report. Even if the cost-benefit of solving global warming is less than suggested by the Stern Report, there is an undeniable ethical case of preventing the deaths of tens of millions of people and the increase in human misery for billions.
Despite the complete failure to produce a new global climate change treaty there are countries and regions taking it seriously. In the UK they have introduced the long-term legally binding Climate Change Act. This Act provides a legal framework for ensuring that Government meets the target of reducing greenhouse gas emissions by at least 80% by 2050, compared to 1990 levels. In Spring 2012 the UK was joined by Mexico who have ratified their own Climate Change national law, which will cut their emissions by 50% by 2050. In the European Union all countries have agree to the so-called 20:20:20 policy by the year 2020. This is a 20% cut in greenhouse gas emissions, 20% increase in energy efficiency and 20% of all energy to be produced from renewable sources.
Despite all the benefits that fossil fuels have brought us we now know that climate change is their side effect and we need to replace them with sustainable carbon-free renewable or alternative energy sources. This is essential, as the power needs of humanity will continue to expand due to the rapid development of China, India, and other countries. For example the IEA suggest that at least 50% of the World’s energy demand for 2030 has yet to be built. As illustrated by the suggestion that China is opening a new coal-fired power station every four days and each year planting more wind turbines than the rest of the world put together. This energy expansion is not limited to the Developing world: in the UK, there will need to be at least another 20 Petawatts of power generated by 2020. The global demand for fossil fuels is so strong and the price high. There is also concern that we have reach ‘peak oil’ and that the World is now running out of oil. This does, however, provide two other reasons why countries should adopt a less intensive carbon-energy sector. First, because the era of power from gas and oil will soon be over, due to a combination of huge global demands and dwindling global reserves. Note, there is concern that stock of high quality coal will be running low by the end of the century. Second, countries have in the 21st century become very aware of ‘energy security’; most developed countries’ economies are heavily reliant on the import of fossil fuels, making them very vulnerable to international blackmail.
Sophisticated political solutions are required at all levels; ranging from a binding international agreement to regional to national to local policies. For example the EU Emissions Trading Scheme is driving down EU emissions, while the UN Clean Development Mechanism tries to drive low carbon investment in Developing countries. At national level the UK is leading the world with the Climate Change Act. The Climate Change Committee, which oversees UK Government policies has proposed a pathway to achieve the 80% reduction by 2050. Their proposal is that over the next 25 years the UK de-carbonise the majority of its electricity generation. After that they will electrify the countries transport network including cars hugely increasing demand for low carbon electricity (Figure 3).
There is also a need for massive investment in sustainable energy generation and low carbon technology, to provide the means of reducing world carbon emissions. This investment should take many forms including tax breaks and cost incentives, proper functioning Green Bank, direct R&D support, investment in Universities and supply line protection. We also need to realise that the word ‘sustainable’ is essential when looking at new low carbon energy technology because a lot of the new technology relies on metals and Rare Earth Elements; and it is well known that China is already trying to corner the market in Rare Earth Elements. In a World when climate change is not going away and regional and global politics will start to catch up with the science we do need some enlightened forward thinking policies to allow the high tech low carbon industries to bloom.
Action on climate change should also always contain an element of win-win. For example supporting a huge increase in renewable energy not only reduces emissions but helps to provide energy security by reducing the reliance on imported oil, coal and gas. Reduced deforestation and reforestation should not only draw-down carbon dioxide from the atmosphere but help to retain biodiversity, stabilize soils and provide livelihoods for local people via carbon credits. Measures that reduce car use will increase walking and cycling, which in turn reduce obesity and heart attacks.
We must not pin all our hopes on global politics, clean energy technology and possible geoengineering solutions, so we must also prepare for the worst and adapt. If implemented now, a lot of the costs and damage that could be caused by changing climate can be mitigated. This requires nations and regions to plan for the next 50 years, something that most societies are unable to do because of the very short-term nature of politics. So climate change along with other global problems challenge the very way we organize our society. Not only does it challenge the concept of the nation-state versus global responsibility, but the short-term vision of our political leaders. To answer the question of what we can do about climate change, we must change some of the basic rules of our society to allow us to adopt a much more global and long-term sustainable approach.