The human ecology of climate change - Climate Change: Biological and Human Aspects - page 392

the contribution of nuclear power is such that there are enough known uranium-
containing geological strata to fuel our current nuclear power industries for over a
century, and more considering that uranium prospecting has not been as intensive as
that for oil. This broad estimate does not take into account fast-breeder options that
would greatly enhance uranium's longevity as a resource. But equally, as mentioned,
this comes with greater technological as well as military security challenges (see
section 8.2.5 on the prospects for nuclear power). Furthermore, since the mid-1980s
(specifically the Chernobyl power-plant disaster in 1986) the growth of the nuclear
industry has slackened markedly. If there was a major international resumption of the
nuclear industry then global uranium resources would need to be reassessed.
With regards to the global commercial energy budget, the factors of resource
availability (or scarcity) and cost compete. Together these largely determine the global
energy resource mix, the fossil contribution of which will determine anthropogenic
carbon releases from energy (sequestration technologies aside). Although overall
reserves of fossil fuels (coal, oil and gas) are enough to theoretically enable carbon
emissions to increase throughout the 21st century, the low r / p ratios for gas and oil
suggest that the consumption of at least oil and gas might peak early in the 21st
century. Estimates that are not based on r / p ratios vary but there is a rough consensus
from a number of analysts (for example Bentley, 2002) suggesting that the peak
consumption of oil and gas might be around the middle of the 21st century. The
options for coal are less restricted and this could make up for any shortfall in gas or
oil should additional alternatives fail to be developed.
In short, such is the likely magnitude of future energy demand that unless non-
fossil energy dominates the global energy mix fossil fuels are likely to continue to
add significantly to the atmospheric reservoir of carbon throughout the 21st century
and well into the next century. Given that to stabilise temperatures we would need
to lower greenhouse gas emissions by around 60% of their 1990 level, and that the
atmospheric residence time of a carbon dioxide molecule is between one and two
centuries, it seems unlikely that global warming will cease over the next few centuries.
Further, in all likelihood human society will have to live with the impacts of further
global warming beyond the 21st century. (Indeed, there will be many centuries'
worth of impact if global warming causes carbon to cascade from biosphere pool to
biosphere pool via the atmosphere in an early Eocene-like Initial Eocene Thermal
Maximum/Palaeocene-Eocene Thermal Maximum (IETM/PETM) event.
In terms of human biology and ecology these climate impacts can largely be
grouped into the related categories of health and food supply.
7.3 Humanhealthandclimatechange
Extreme weather events, such as the heatwaves of north-east North America and
Western Europe in August 2003, according to some climate models, are thought to
be associated with global warming (see section 6.6.1; Meehl and Tebaldi, 2004). The
weather, it is said, is a traditional topic of conversation associated with the British. It
should therefore not be surprising that when extreme weather events take place the