Uncertainty, unclear risks and compromised commitments

Considering the predicted impacts of anthropogenic (human-caused) global warming on Southasia, the region has reasons for concern and immediate action. Yet the science of the current global warming, and of climate change in general, is still emerging and the level of public information on this in this region is quite low. In the absence of a good understanding of the science behind natural processes that go against human expectations, they are quickly stamped as 'natural disasters'. The uncertain knowledge base and inaccurate descriptions of risks for Southasia have created obstacles to a clearer identification of adaptation measures needed for the Subcontinent. Wider knowledge of climate science is thus essential to promote informed responses to global warming and climate change.

The post-Kyoto Protocol global politics that has emerged in relation to mitigation makes the future of reductions in greenhouse-gas emissions uncertain. In December in Copenhagen, the Conference of the Parties of the United Nations Framework Convention on Climate Change will address both the science of global warming and the politics of a global response to it. To discuss these and related issues, the editors invited N Sundararaman, an expert on atmospheric sciences based in Geneva who was associated with the Inter-governmental Panel on Climate Change from its inception as general-secretary, and Jayanta Bandyopadhyay, expert on sustainable development policy and water-systems management, based in Calcutta.

JB: Perhaps because of the widespread media coverage, the IPCC has captured the public imagination, even though climate change and now the current global warming had been the object of research for many scientists over the last two centuries. This part of the history of atmospheric science can constitute important public knowledge. Can we start by discussing the contributions of some of the scientists prior to the establishment of the IPCC?
NS: I will hit on some of the highlights. The problem of the effect of carbon dioxide on the Earth's 'radiation balance' – roughly, its climate – was first discussed in the mid-1890s by Arrhenius, the Swedish chemist. During the International Geophysical Year, July 1957 to December 1958, an observation station was set up in Hawaii by the US National Oceanic and Atmospheric Administration, in order to measure atmospheric carbon dioxide. Based on data from this installation, researchers were able to establish unmistakably the trend of increasing carbon dioxide. Thereafter, a series of pioneering papers were able to look into the uptake of carbon by the oceans and the plausible temperature increases due to the fraction remaining in the atmosphere.

From about 1960, a fairly large number of climate scientists in North America, the USSR and Europe were engaged in climate-change studies. Some of this research was based on physical data, such as that from tree rings, while other studies were based on computer models. In 1960, two scientists at Princeton, Syukuro Manabe and Richard Wetherald, made a one-dimensional computer-model calculation of the likely temperature increase for a doubling of the carbon-dioxide concentration in the atmosphere. That calculation still has validity today. Around 1974, a panel with the US National Academy of Sciences exposed the problem and discussed all aspects of the science, an exploration that was also done in the UK and in one or two other Western countries. That same year, V Ramanathan published his seminal paper showing that greenhouse gases other than carbon dioxide also needed to be taken into consideration.

Also in the early 1970s, the US Department of Transportation undertook a four-year study on the effect of engine emissions of high-flying aircraft on stratospheric ozone, called the Climatic Impact Assessment Program, or CIAP. CIAP also examined the effect of depleted stratospheric ozone and of engine-generated aerosols on Earth's climate. Importantly, these models subsequently succeeded in marrying atmospheric chemistry with meteorology. Within a few years, scientists were able to pinpoint the consequences of aircraft emissions for Earth's climate.

At the international level, in 1985 a conference was held in Villach, in Austria, for which I was the rapporteur for the section on non-CO2 greenhouse gases. Two years later, a resolution by the Tenth World Meteorological Congress and subsequently by the UN Environment Programme led to the establishment of the IPCC.

There exists an important gap in public knowledge on the basics, starting from the various possible future scenarios for greenhouse gas (GHG) emissions, predictions of expected warmings, which are used to predict changes in the climate – for instance, precipitation, rainfall intensity, extreme events, etc. The new climate scenarios are then used to identify probable risks or advantages regarding – for example, new water regimes or changes in vegetation patterns. A significant obstacle is that the global climate model is not very accurate for predictions on smaller areas, like a river basin. The other models used in related prediction of risks may also produce diverse results. The uncertainty that is integral to climate modelling needs to be reduced for more useful forecasts of future changes. There is a serious debate going on in this connection, and Professor Mike Hulme of the University of East Anglia, in the UK, has raised doubts about the correlations that are being made between the uncertainty of modelling with assessment of risks. You have been closely associated with modelling exercises during the IPCC process. How dependable are climate predications in helping craft effective policy, and what are their weaknesses? What should the priorities be – for the UN and the national governments – in rectifying any such weakness in such an important context?
There are about a dozen 'fully coupled', three-dimensional models being used today, meaning that they bring together data on atmospheric circulation, radiation transfer, atmospheric chemistry and the oceans, and which use all available climatological data. Furthermore, the IPCC always estimates the error for all its conclusions, and specifies the methods it uses for these estimates. Models do yield scattered results, but the error estimates are made on an understanding of this scatter. Thus, the projection for global temperature increase, along with these error estimates, provides the most reliable piece of state-of-the-art data – there is simply nothing else available today.

There is an inherent difficulty in calculating temperature change on smaller scales, and that difficulty increases as one gets to smaller and smaller scales. This is true also of weather predictions. Generally, regression techniques are used for making projections for smaller scales. These techniques use observed correlations between the local values of weather/climate variables such as temperature, and the projections for those variables which global models yield for that region. The regional values themselves are obtained through interpolation of global projections of the respective variable. The global projections, as stated earlier, are quite reliable, and one knows the error associated with them. The opposite difficulty is experienced in impact studies. Here, almost all research is done on local or regional scales, and to upscale these to the global level is very difficult.

But all of this does not negate the value of projections of future global temperatures and their environmental and societal consequences for use in guiding policymaking. For example: Do we know that the global mean surface temperature has increased since instrumental observations began? Yes. To what can one attribute the observed increase in the last half-century? To greenhouse-gas emissions, undoubtedly. Are greenhouse-gas emissions increasing? Yes. Do we know the atmospheric 'residence times'  of these gases?[the duration of the presence of any gas in the atmosphere after its emission. In the case of carbon dioxide, this is 150-200 years]  Yes. How do we know that we are not in a cycle of natural climate change that may also account for the observed temperature increase? To the extent that we know the natural causes – solar output, volcanic eruptions – we have incorporated these into the models. The natural causes alone, however, fail to explain the observed increase.

Do we know that water availability will be affected in a warmed world? Yes, because a warmed atmosphere will hold more moisture, which at some point has to be precipitated out. All the water in the atmosphere is recycled as snow, rain, water vapour all the time. It is hard to give a number for the increased volume as excesses (resulting in flooding) and deficits (droughts) will occur; these departures from the mean will be difficult to predict on a year to year basis. We are quite confident that there will be increased precipitation in the global average but its distribution pattern will undeniably show inter-annual variations. The time-and-space distribution of this increased precipitation will be different from today. All these are definitive guideposts for policymaking. As regards extreme weather events, we are very confident of an increasing number of excessively hot days and warmer nights and general increase in the storminess. The trend will be an increasing one; but this does not mean that these will increase every year, year to year.

The most difficult problem in projecting future climate, in my view, is that of clouds – their formation, altitude, persistence and content, this last meaning water or ice. This is a fundamental difficulty. The next are the 'positive feedbacks', or the effects of global warming that contribute to further warming. Some of these are well known – for instance, sea-ice melting; others are less so, such as the escape of greenhouse gases from permafrost, boreal forests and the tundra. In order to make projections on smaller scales more reliable, we need global coverage of observations, whether it be soil moisture, sea level, glacier melt, temperature, precipitation, flora and fauna, desert encroachment or whatever. We need satellite observations with improved techniques. But our own experience, though subjective, also counts. Improved observations at the local and regional scales can contribute much.

What can the UN and countries do? Neither the UN nor its specialised agencies can do much directly, as everything has to be done by the member states. Observations, observations, observations – that is the name of the game.

The Fourth Assessment Report (AR4) of the IPCC, released in 2007, predicts changes in the climate of Asia, particularly Southasia, that are not conducive to such a densely populated region with hundreds of millions living in poverty. The impression that major rivers of Southasia originating in the high Himalaya, like the Ganga or the Brahmaputra, may become seasonal by 2050 would be a matter of serious public concern. The predictions of floods and droughts becoming more frequent also do not augur well for the region. Within the level of accuracy of the predictions, there has been quite a generalisation in making predictions, particularly on the Himalaya. In your opinion, how credible are these predictions on the Subcontinent?
The Himalayan glaciers are retreating, as are glaciers elsewhere. A warmed world leads one intuitively to expect accelerated glacier melt. A warmed world will also have increased precipitation, and some of it will be snow – snowfall will most likely increase. The question is one of balance between snowfall, snowmelt and glacier melt. Will falling snow have enough time to accumulate, compact and increase the glacier mass? Or will it melt quickly, as spring temperatures rise? My physics tells me that melting will increase as temperature rises. As such, we'd better hurry up and secure our water future; we'd better prepare for better water management. No enemy needs to come from outside to threaten our sovereignty: our profligate use or wanton pollution of water can do it.

Precautionary steps to mitigate the GHG emissions, as well as the establishment of adaptation mechanisms worldwide, is an urgent task of the global community. Yet, right from the Earth Summit in 1992 through to the Kyoto and Bali conferences that followed, inter-governmental processes have not been successful in bringing about the expected reductions in GHG emissions. All the while, market mechanisms have led to the commoditisation of the atmosphere, which makes room for continued pollution of the atmosphere against payment. The industrialised countries, especially the USA, have not succeeded in emissions reduction; national-level priorities are standing in the way of global-level solutions. Why should the global public be hopeful that the Copenhagen Summit has any chance of success?
We must not give up hope. Kyoto was the first expression of the political will on the part of Annex 1 countries [the 36 industrialised countries] to acknowledge the threat by taking the first step. The US now has a new administration, which is committed to green energy and green employment. One cannot second-guess the US position at Copenhagen. Meanwhile, the atmosphere does not know nor care where the greenhouse-gas molecules originate. In the past, almost all of them were originating in the Annex 1 countries. But today, that accumulation has already occurred, while future emissions will add to the pool. Either way, accumulations of greenhouse gases in the atmosphere will lead to greater warming, the consequences of which will be felt by all. And those consequences will be worse for non-Annex 1 countries, due to their lack of financial and institutional resources to handle those consequences.

Equity and 'polluter pays' are important principles, but how far can they be extended or tested remains to be seen in the context of globalisation and concerns over competitiveness. All countries, particularly non-Annex 1 countries, need to vigorously pursue so-called 'no regret' actions – actions that are good for society and improve its well-being, regardless of whether or not the projected impacts will occur – in their own national interest: improve energy, water, food and health securities by every available means, be it from within or without. Improving energy and food securities alone with sustainable approaches will reduce greenhouse-gas emissions. The dilemma of global warming is that the gases causing it arise from human activities aimed at feeding itself and living better than its ancestry.

A crucial issue in the FCCC negotiations is the linking by the USA of its emissions reduction with commitments to emissions capping by rapidly industrialising countries, such as China and India. In 1992, an article entitled "Global Warming in an Unequal World", written by Anil Agarwal and Sunita Narain, showed the inequity in per capita GHG emissions among different nations. However, while the per capita national averages exposed the climate inequity at the international level, it covered up the inequity at the intra-national level, within the countries. Today, the time has come to reach a new understanding of the term 'climate equity', one that is equally sensitive to the unequal world within the nations. While everyone in Southasia, for instance, is saying that the poor will be most seriously impacted by climate change, the question arises as to whether we can have some measures of global equity for the poor in the coming decades. We need to safeguard the world's poor from being penalised for GHG emissions, produced largely by the rich in their countries. Do you have any suggestions in this respect?
Throughout history, the poor have certainly suffered an un-equitable burden of misery and injustice. What the Indian experience has shown by the revolution in information technology, and the ensuing burgeoning middle class, is that it is not a question of rich or poor but rather of qualified and not qualified. Education is where many of the answers can be found – universal health care and universal education. Here I will push the equity argument to the limit and squeeze every penny, paisa, kopek or whatever from whomever. Like the global commons, one should talk of the global poor.

As regards mitigation, reduction of GHG emissions is imperative if we wish to avoid a catastrophic warming of the atmosphere. Such action on mitigation depends largely on the success of the UNFCCC negotiations. We are already hearing about a post-Kyoto climate policy, and hopefully this will open up the path for early mitigation. On the other side is adaptation, independent of such mitigation measures. This is critically important for all parts of the world. All the same, without real progress on mitigation, adaptation will have a very limited impact. In the backdrop of the forthcoming Copenhagen conference, in many parts of the developing world today, donors and INGOs are holding conferences on adaptation, while no serious discussion is taking place on the vital dependence of adaptation on early progress in mitigation. Support to adaptation in the developing world does not mean a reduction in the urgency with respect to mitigation. Is this a worrying trend? Yes, adaptation will become increasingly difficult and resource-intensive if little progress is made on mitigation. Mitigation is so closely associated with global competitiveness and standards of living that major action will be like pulling teeth with one's bare hands. Conferences and their funding? That is the nature of the beast: talking heads talking to other talking heads, spouting endless repetition of the same material. What is needed is clearly less chatter and more action. It was in this context that I realised that informing, say, women's groups on these issues would be a far more productive approach than talking to policymakers or the media. Can we think of a clever, foolproof way of doing this?

We have covered a wide range of topics, but still there are many left. How humanity addresses the challenge posed by global warming and climate change will have very important implications for its future. The future of energy, transportation, water systems management, agriculture, industrial technology, among many others, is linked to this. At this juncture, as a professional so closely connected with climate-related research and global negotiations, tell us what we can expect from the forthcoming Copenhagen conference?
Search me. Almost always, international negotiations end up at the lowest common denominator. Perhaps promotion of less-carbon-intensive primary-energy supply can be agreed to as an overarching principle for two decades after 2012 by all parties, and more funds can be made available for adaptation measures. Perhaps, technologies can be agreed to be made available on a no-cost basis for the non-BRIC [Brazil, Russia, India, China] developing countries to move away from carbon energy. BRIC is a challenge. I also think we need to be relentless in increasing observations, as this will clearly tell us the pace at which warming is occurring and, ipso facto, what time scale is available to manage it.

Lastly, do you think the focus on climate change takes away from the environmental problems of yore – deforestation, soil erosion, local pollution, etc?
On the contrary, the current global warming is highlighting those problems. The warming is an additional stress – in some cases, the major stress – exacerbating these problems. The traditional environmental problems and global warming are not either-or choices. They are 'and & and' issues.

~ Jayanta Bandyopadhyay is a professor and head of the Centre for Development and Environment Policy at the Indian Institute of Management in Calcutta.N Sundararaman is an expert on atmospheric sciences based in Geneva. He was general secretary of the Inter-governmenal Panel on Climate Change (IPCC) at its inception.