It seems to me that, over the next 20 years or so, people in
Western democracies are likely to suffer to a greater extent from the
consequences of an explosion in public debt than from climate change. At the
same time, I acknowledge that climate change could possibly pose a serious
threat to civilization and perhaps human survival. The chart shown above is my
attempt to illustrate how those risks might be compared.
I make no claim to expertise in assessment of climate change
risks. My reading on the topic suggests that the theory that increasing
concentrations of greenhouse gases in the atmosphere are contributing to
climate change is widely accepted by scientists. However, people with relevant
expertise obviously have different views about the rate at which climate change
is likely to occur, the contribution of human activity, the political feasibility
of various forms of remedial action, and the adaptability of humans and other
living creatures.
In my view, too little attention has been given to “tail
risk” associated with climate change – the low probability that climate change
will result in a great deal of human misery, as shown in the chart above. As I
have written here previously, if you are concerned about climate change, you (like
me) are likely to be more concerned about the remote possibility that your
great grandchildren might suffer from having to live with potentially
catastrophic climate change outcomes than about the more probable
outcome that climate change might cause their incomes to be somewhat lower than
economic modelling suggests they would be otherwise. I have also previously expressed
agreement with Nassim Taleb
that there are some risks we should avoid if possible, even though there is a
low probability that they will occur at any point in time. In order to
flourish, future generations need to be able to survive.
The reasoning
behind the rest of the chart requires more explanation. Why do I think there is
a 95% probability that the citizens of western democracies will suffer as much
or more over the next 20 years from an explosion in public debt than from climate
change? Since I don’t have either the inclination or expertise to weigh up the
technical evidence on climate change for myself, I tend to rely on the IPCC’s assessments.
I suspect the authors of IPCC reports are still somewhat biased toward
attempting to present a view favouring urgent international action to reduce
greenhouse gas emissions. Nevertheless, after they have been modified in the
light of expert public scrutiny, the IPCC reports are probably the most
authoritative source of independent assessments of the relevant evidence.
The IPCC’s
assessment of likely climate change outcomes in Chapter 3 of its recent special
report, Global
Warming of 1.5 ÂșC, implies that we can expect some
fairly serious adverse consequences over the next few decades:
“The
impacts of climate change are being felt in every inhabited continent and in
the oceans. However, they are not spread uniformly across the globe, and
different parts of the world experience impacts differently. An average warming
of 1.5°C across the whole globe raises the risk of heatwaves and heavy rainfall
events, amongst many other potential impacts. Limiting warming to 1.5°C rather
than 2°C can help reduce these risks, but the impacts the world experiences
will depend on the specific greenhouse gas emissions ‘pathway’ taken. The
consequences of temporarily overshooting 1.5°C of warming and returning to this
level later in the century, for example, could be larger than if temperature
stabilizes below 1.5°C. The size and duration of an overshoot will also affect
future impacts.”
However, a
recent OECD report on Greece, which is fairly optimistic about the future of that
economy, seems to me to illustrate that public debt crises are likely to result
in much more human misery than climate change over the next few decades:
“Despite
these positive developments, challenges abound. GDP per capita is still 25%
below its pre-crisis level. The public debt is still high and a source of
significant vulnerability. Poverty rose sharply during the crisis, especially
among the young and families with children. Though poverty has stabilised, it
remains near a record high. Skill mismatch is also high and investment remains
depressed. This contributes to low productivity – which has fallen further
behind other OECD countries – and low wages – resulting in high in-work
poverty. Though improving, female labour participation is among the lowest
across OECD countries. The recovery in investment is held back by a dearth of
finance – due in part to high levels of non-performing loans and to capital
controls – high cost of capital relative to wages, cumbersome regulations and
low demand. These problems weigh on people’s well-being”.
As I
explained in a recent post, there are strong reasons to expect that the failure
of governments in most OECD countries to restrain the growth of government
spending is likely to cause debt servicing to become a more widespread problem
in the decades ahead. I think the most likely outcomes in most
western democracies will probably be much worse that the outcomes of climate
change, although not be as bad as the experience of Greece over the last
decade. The chart above is drawn to acknowledge that there is some possibility
that democratic governments will lift their performance, or world interest
rates will remain low, so debt servicing may not be a problem.
The modest
adverse outcomes depicted on the right side of the chart might well be offset
by positive factors. There is a good chance that over the longer term the positive
impacts of technological advances will be sufficient to offset the negative
impacts of both public debt accumulation and climate change, but it would be
excessively optimistic to expect rapid technological progress and productivity
growth in western democracies over the next 20 years.
Some
readers may object to my attempt to compare the risks associated with climate
change and public debt explosion on the ground that these are very different
risks when viewed at a national public policy perspective. There obviously isn’t
much the government of any country can do to reduce climate change risk by
acting alone.
However, I
have drawn the chart with individual well-being in mind. From an individual’s
perspective, the risks surrounding climate change and public debt are quite
similar. Nothing that individuals do by themselves will make much difference to
national or global outcomes. Voting might appear to provide an avenue for
individuals to influence national outcomes but, as others have observed, voting
in a national election is like ordering a meal from the menu in a restaurant
and being served the same meal irrespective of what you order.
There are
options that individuals can consider to reduce their exposure to both climate
change and public debt risks. For example, consideration of climate change risk
might influence decisions about housing location and construction, and consideration
of public debt risks might cause individuals to reduce the extent that their
families rely on government for health services, education and retirement
incomes.
It strikes
me that climate change and the risks of public debt explosion also pose similar
ethical issues for individuals. Does the fact that an individual’s actions,
considered in isolation, has a negligible impact on global and national problems
absolve him or her of an obligation to moderate his or her contributions to
those problems? I think not, but I will leave consideration of the issue for
another time.