What are the heat content and net thermal flux of the ocean basins, and how are they changing over time?

The answers are necessary for accurate climate modeling. The difficulty will be the expense of placing and monitoring the large number of sensors required (at least tens of thousands, perhaps many more).

Is nature predictable?

Earth systems have a natural tendency to be complex, i.e. several processes act at the same time. The process-response function is therefore logically complex, i.e. not dependant on one process. Earth system sciences have become almost purely empiric and a theoretical approach is required to provide a sound basis for models. Partly deterministic, partly probabilistic model runs for all permutations of variables should then tell us whether the system is predictable. This requires a joint effort of earth scientists, climatologists, physicists, chemists, biologists, mathematicians, statisticians, modellers, and many others.

How do we develop coupled climate-social models that take human society into account?

We need to establish a robust relationship between human society and climate/exploitation of nature. Otherwise the underlying pressure for growth will lead undesirable situations.

What are the missing observations to model the Earth system as an open system?

One of the main difficulties for modeling the Earth system (or sub-systems) is to idenfy and characterize all source and loss terms. As an approximation one often assumes that the system is closed or enclosed in a closed system. According to the domain which is considered, such an approximation may be wrong. More accurate observations are still needed.

What are the regional expressions of climate change?

Over the last decades and years, the question of climate change attribution has been resolved scientifically and we have made good progress in constraining the magnitude of greenhouse warming at a global scale. In contrast, the regional expression of climate change is still poorly understood, hence providing a vague physical basis for foresighted political decisions and socioeconomic planning.

Gaps to fill in our knowledge on regional climate relate to regional trends and magnitudes of monsoon precipitation, drought in subtropical regions of both hemispheres, Arctic warming (including melt of sea ice and Greenland ice), prevalent climate modes and seasonality in mid-latitude regions, etc.

Focused research over the next decade should be able to constrain many of the uncertainties about the regionally relevant aspects of climate change. Such research needs to address regional climate dynamics across past and present timescales, based on targeted, high-resolution climate modeling and the generation and analysis of detailed paleo-climate reconstructions and climate-observation datasets. Without better-founded expectations about regional changes, any research on global change impacts and adaptation measures will be built on sand and remain speculative.

How should climate models evolve in order to provide sound information for impact assessment and scenario development?

It is often pointed out that IPCC AR4 put an end to the debate on “reality” of global change. The role of climate models will accordingly be changed. A possible direction is to utilize model results as bases for impact assessment for global change and in turn scenario development. What are the deficits and possible improvements of current climate models when applied for impact assessments? Communications among different disciplines are requited to answer this question.

What are earth system thresholds that are sensitive to biotic impoverishment?

Through the predominant period of the rise of humanity as the dominant species (the Holocene), earth system properties have been relatively benign with respect to the constraints within which the current biosphere remains viable. We are distracted by climate change to the point that Heinrich events, Dansgaard-Oeschger events, and the Bølling-Allerød transition draw us away from the more basic scientific issue as to why climate remains largely within boundary conditions conducive to life on Earth. It is also possible that the question of global biotic thresholds is mistakenly assumed to be some form of Gaia-Hypothesis like thinking, a topic which has some strong supporters, but is largely unpopular among many scientists. Because there is likely to be an immense suffering in the face of climate change, it would be inappropriate to suggest that such questions should not dominate our attention – they deserve substantial, immediate attention. Climate change research, however, in its current form, incorporates enormous “black boxes” and this is not the best science. GCM models tax even the best super computers, but until such models contain hundreds of ecosystem types, each made up of hundreds of functional species types, and contain key interactions among species and their environment, we are avoiding the true challenge before us – to understand Earth systems in its entirety – physical, chemical, and biological with spatial and temporal accuracy all coupled to social systems.

The Millennium Assessment achieved an unprecedented consensus among natural and social scientists from around the world declaring that the most pervasive environmental problems we face are caused by the massive spending down of natural capital – our biodiversity and our natural resources. Thirty years ago no one might have imagined we would have multi-million dollar, international efforts and intergovernmental panels seeking to understand the global carbon cycle and its relationship to climate using the most advanced research methods and techniques ever developed. Yet, the scientific foundation for this endeavor can be traced back to Arrhenius in 1896. To wait a similar period to build upon the Millennium Assessment’s findings would leave us facing problems in the future that were readily addressed today.

Given rates of local and global extinction, tt is difficult to imagine any challenge greater and more urgent than identifying earth system thresholds sensitive to biotic impoverishment.

Which of the coping strategies of local communities with changing climate and consequent environmental risk have become stronger and which one weaker in different regions of the world?

while Honey Bee network ( www.sristi.org) has demonstrated the power of creative and innovative coping strategies in dealing with increasing risks, uncertainties and declining institutional access, there remains a great deal of need for mapping these coping strategies worldwide. After all, without strengthening such strategies, no major model or policy framework can succeed ever. I often find as I did in IFPRI workshop on priority setting for cgiar systems that mostly, model builders carry their day disregarding the ground realities and the complexity involved therein. be it gender issues, systematic neglect of certain parameters on which data is neither collected nor analysed, or institutional redesign.

i have seen this in the millennium ecosystem study as well, only lip service was paid to such issues, i will not be surprised if you choose to neglect this question again.
prof anil k gupta iim ahemdabad anilg@iimahd.ernet.in

How much, and what, global climate change will climate models project for the next 20-30 years, when taking into account both natural and anthropogenic forcing?

How much of the global climate change for the next 20-30 years as projected by the climate models with both natural and anthropogenic forcing? The projections of the global climate change as shown by the IPCC WG1 four reports are only considered the anthropogenic forcing scenarios. The predictions of the natural climate change that is very important are ignored.

How will anthropogenic factors change local weather systems? Where are the areas most vulnerable to a change in the weather which could significantly affect the ability of their human population to survive?

Any change in the climate system will affect different areas to different extents. Some places (particularly in poorer countries) rely on growing food locally and do not have the infractructure to deal with large weather fluctuations. We need to understand how changes in large atmospheric and oceanic systems affect weather on smaller scales in order to provide support to those communities and protect nearby wildlife habitat.