Geoscience Reference
In-Depth Information
but turned out to be small in comparison to the chain of events that followed. In
themselves, these shocks could have been expected to cause a pause in growth,
but not one that would throw history from its course. But each shock was large
enough to exceed some threshold of society's capacity to cope with change.
In each case, what might have been a recession of substantial but ordinary
magnitude became a great depression. The associated social convulsions changed
political institutions fundamentally and as permanently as human institutions
can be changed. They shifted the whole trajectory of political stability and
economic growth.
The 2008 Review was written before the critical phase of the Great Crash
of 2008 was precipitated by the collapse of Lehman Brothers in September
2008. The timely, powerful and concerted fiscal and monetary expansion in
the substantial economies in late 2008 and through 2009 prevented the worst
possibilities from that immense financial shock (Garnaut with Llewellyn-Smith,
2009). Nevertheless, the shock of the Great Crash to European and United
States financial and political life has left a long-term legacy of economic under-
performance that has led to loss of incomes that greatly exceeds the scale of
the original shock, and which may yet prove too large for stability in globally
important national and international institutions.
Unmitigated climate change, or mitigation too weak to avoid dangerous
climate change, could give human society a shock larger than any imposed by
1890s, 1930s, late 1990s or 2000s fractures in the global financial system.
Every degree of warming above 2°C increases risks and costs by large
amounts. Warming of 4°C and more would precipitate such large change in
global economic and political conditions as to force the reshaping of national
boundaries. It may lead to a small number of more effective states combating
anarchy by absorbing others. It may lead to extended anarchy. The survival of
states with anything like current boundaries and roles would be one of the less
likely eventualities.
The case for strong mitigation is a conservative one. With the advent of a Four
Degree World, we can be sure that the challenges to critical institutions would
be considerable … and that some would fail.
Here we are talking about failure with global consequences. A shock from
weakly mitigated climate change could unhinge Australian political and
economic stability. But even if there were no such direct effect, there would be
no islands of stability in Melbourne or Mildura if sea level rise displaces from
their homes a substantial proportion of the people of Bangladesh and West
Bengal, and many in the great littoral cities of Dhaka, Kolkata, Shanghai,
Guangzhou, Ningbo, Bangkok, Jakarta, Manila, Ho Chi Minh, Yangon, Karachi
and Mumbai. If changes in monsoon patterns and to the flows of the great rivers
from the Tibetan plateau disrupt agriculture among the immense concentra-
tions of people that have grown around the reliability of water flows from this
area since the beginning of human civilization, it will not just be a problem
for the people of India, Bangladesh, Pakistan, Vietnam, Myanmar and China.
