Sustainability and policy - Climate Change: Biological and Human Aspects - page 512

and poorer nations. This in turn will have biology-related impacts on poor-nations'
population health and longevity as well as reducing their ability to pay for climate
change impacts. Even so, such is the magnitude of likely energy demand, even before
the middle of this century (see Figure 8.10), that the required growth in non-fossil
energy generation will be unprecedented. This is not impossible but, as with climate
change itself, it is new territory.
With regards to the developing and developed nations, carbon emissions and eco-
nomic growth have been the subject of some discussion about compromise, and indeed
it can be found in the Kyoto Protocol. This is the idea of contraction and convergence.
The developed, wealthy nations would switch to a low-fossil, high-energy-efficiency
economy and so contract or reduce their carbon emissions. Meanwhile, the develop-
ing nations would be allowed some leeway and so increase emissions. In this way the
developing and developed nations, on a per-capita basis, would see their respective
levels of emissions converge. The problem at the moment (since Kyoto) is that the
wealthy developed nations en masse are not contracting emissions but increasing
them, and the developing nations are similarly raising emissions. At the moment
(at least) our species is firmly on a high-emission IPCC scenario track and, despite
international rhetoric by the Kyoto nations, there seems little prospect of this changing
(indeed, 5 years on from this topic's first edition the high end of the high-emission
track seems more likely). Climate change and climate change impacts are therefore
not only inevitable but could be more towards the extreme ends of the range discussed
in this topic.
The consequence of this is that not only will we have to adapt to our currently
slightly warmer world but we will need to make greater adaptations to an even
warmer world in the mid-21st century and beyond. Of importance to policy-makers,
the question is almost certainly no longer one of expenditure on either adaptation
or greenhouse-emission mitigation, but expenditure on both, or paying for the con-
sequences (namely the range of climate impacts and fossil fuel scarcity).
8.5 Futurehumanandbiologicalchange
Anthropogenic (human-induced) climate change is undoubtedly taking place. We
can measure greenhouse gas concentrations in the atmosphere and their respective
heat-absorbing properties in the laboratory. We have detected how their atmospheric
concentrations have fluctuated in the past: for example, between significant climate
(glacial and interglacial) swings. We know that other factors also affect the global
climate, within certain margins of error, depending on the factor being considered.
So, the case for human activity causing climate change is virtually conclusive, even
if the exact detail is unclear (Chapter 1).
What is a little less certain is whether we are in the process of triggering a biosphere
event like the Initial Eocene Thermal Maximum/Palaeocene-Eocene Thermal Max-
imum (IETM/PETM). There is less evidence for this and considerable uncertainty
as to the environmental thresholds that would have to be crossed to initiate such an
event. Only in recent years has there been concern that the amount of carbon being