Managing climate risk
NITIN DESAI
THE year 2021 saw many countries experiencing exceptional weather
extremes. Temperatures reached 500C in Western Canada and the US; record high
temperatures were seen in many parts of the Mediterranean; a monthÕs worth of rain
falling over just a few days led to floods in Europe and China; India
experienced long dry spells and heavy rain during the summer and now the winter
monsoon; for the first time rain instead of snow fell on the Greenland ice
sheet; there was a second year of
drought in South America; forest fires raged in many parts of the world
including in Siberia because of exceptionally high temperatures.
Many of these
extreme weather events have been attributed by scientists to long-term changes
in the average temperature of the earth, a trend that we call climate change.
Scientists have warned the world about this trend for several decades and their
forecasts have become increasingly alarming. That and the widespread experience
of weather extremes has led to a greater sense of urgency in addressing climate
change related risks. What follows spells out these risks and what needs to be
done globally to mitigate them.
The earth is
habitable because of the presence of carbon dioxide, methane and other
greenhouse gases (GHGs) in the atmosphere. In the absence of these GHGs the
average temperature of the earth, at which incoming and outgoing radiation are
in balance, would be around -190C, a level at which human and most other
life forms cannot be sustained. The GHGs in the atmosphere reflect back to
earth some of the outgoing radiation and raise this average temperature to a
higher level, which at present is around 150C. This
average temperature has fluctuated up and down through the earthÕs history of
ice ages and thaw periods. However, these changes took place slowly over
centuries or even millennia.
Our concern
today is that we are facing the threat of substantial temperature rise over a
much shorter period measured in years and decades. The accumulation of greenhouse
gases that we see now is huge by historical standards. In 2019, atmospheric CO2 concentrations were higher than at any
time in at least two million years, and concentrations of CH4 and N2O were higher than at
any time in at least 800,000 years. The bulk of the increase has taken place
after the industrial revolution that increased the use of carbon dioxide
emitting fossil fuels and much higher economic and population growth,
particularly after 1950.
Because of the
accumulation of GHGs an increase of about 10C has
already taken place relative to the average temperature in the last half of the
19th century. Global surface temperature has increased faster since 1970 than
in any other 50-year period over at least the last 2000 years. Moreover, it is
now clear that most of this temperature increase is because of human
activities, most particularly the use of carbon-based fossil fuels like coal,
petroleum and gas. This much faster rate of temperature change leaves little
time for ecosystems and human beings to adjust to a higher temperature
environment and poses major threats of disruption and distress. That is the
climate risk that the world community is now trying to address.
The concern about climate change linked to
anthropogenically induced temperature rise led in the late eighties to
governments agreeing within the UN framework to establish a scientific body for
building a consensus on the facts and projections about climate change, the
Inter-governmental Panel on Climate Change (IPCC).
The most recent
report of the IPCC,1 that is
part of its sixth assessment which will be completed only in 2022, has pointed
out that each of the last four decades has been successively warmer than any
decade that preceded it since 1850. Global surface temperature in the first two
decades of the 21st century (2001-2020) was 0.99¡C higher than 1850-1900. When
it comes to consequences of the temperature rise, the Report states that
* Globally averaged precipitation over land has increased since
1950, with a faster rate of increase since the 1980s.
* Mid-latitude storm tracks have likely shifted poleward in
both hemispheres since the 1980s, with marked seasonality in trends.
* Human influence is very likely the main driver of the
global retreat of glaciers since the 1990s and the decrease in Arctic Sea ice
area between 1979-1988 and 2010-2019.
* Human influence very likely contributed to the decrease in
Northern Hemisphere spring snow cover since 1950.
* The global upper ocean (0-700 m) has warmed since the 1970s and
human influence is the main driver and human-caused CO2 emissions are the main driver of current
global acidification of the surface open ocean.
* Global mean sea level increased by 0.20 m between 1901 and 2018.
The IPCC report also focuses on extreme
weather events. It has assessed that the 10C
temperature rise that we have experienced so far has increased the incidence of
hot temperature extremes that came once in ten years in the last half of the
19th century to 2.8 times now. If the average global temperature were to
increase by 1.5-20C this would go unto 4.1-5.6 times a decade. A similar
comparison for heavy precipitation shows an increase of 1.3 times now and
1.5-1.7 times with a 1.5-20C temperature rise and of droughts to 1.7
times now and 2-2.4 times with a 1.5-20C temperature rise. Apart from this we will
face a rising incidence of cyclones and storms and sea water intrusion in
coastal areas because of the rise in sea level because of the temperature rise.
The global forecasts are helpful. But for
effective management we also need regional assessments as the impact of the
temperature rise will vary from place to place. A recent assessment of climate
risks that India faces was prepared by the Department of Earth Sciences2 and a summary of that is as follows:
* The annual mean near-surface air temperature over India has
warmed by around 0.7¡C during 1901-2018 with the post-1950 trends attributable
largely to anthropogenic activities. Atmospheric moisture content over the
Indian region has also risen during this period.
* Sea surface temperature (SST) in the tropical Indian Ocean has
risen by 1¡C on average over 1951-2015 and is projected to increase further
during the 21st century.
* Despite the rise in temperature, there has been a declining trend
in summer monsoon precipitation since 1950 with particularly notable decreases
in parts of the Indo-Gangetic plains and the Western Ghats attributable to the
cooling effects of aerosols and land use changes, which have more than offset
the precipitation enhancing tendency of GHG warming in the past 6-7 decades.
* The frequency of localized heavy precipitation occurrences has
risen significantly over Central India in the past 6-7 decades.
* Warming due to increasing concentration of atmospheric GHGs and
moisture content is generally expected to strengthen the Indian monsoon and
climate models project a considerable rise in the mean, extremes and
interannual variability of monsoon precipitation by the end of the century.
* India has witnessed a higher frequency of droughts and expansion
of drought-affected areas since 1950.
* Flooding events over India have also increased since 1950, in
part due to enhanced occurrence of localized, short-duration intense rainfall
events and flooding occurrences due to intense rainfall are projected to
increase in the future.
* Higher rates of glacier and snowmelt in a warming world would
enhance stream flow and compound flood risk over the Himalayan river basins.
The Indus, Ganga and Brahmaputra basins are considered particularly at risk of
enhanced flooding in the future in the absence of additional adaptation and
risk mitigation measures.
* The North Indian Ocean (NIO), the ocean near India rose at a rate
of 3.3 mm per year during 1993-2017 similar to the global mean sea level rise.
* The frequency of very severe cyclonic storms over the NIO during
the post-monsoon season has significantly increased in the past two decades and
with continued global warming, the frequency is projected to further increase
during the 21st century.
* The Hindukush Himalayas (HKH) underwent rapid warming at a rate
of about 0.2oC per decade during the last 6-7 decades and
experienced a significant decline in snowfall and glacial area in the last 4-5
decades.
Quite simply, the way things are going our
children and grandchildren will live in a world with many more hot spells with
temperatures going up to 500C, much more rain on fewer days, frequent
floods, intrusion of sea waters in coastal areas and more cyclones and storms.
The atmosphere of the earth is shared by all living things on earth
and the accumulation of greenhouse gases does not respect any political
boundary. But the actions which have to be taken to address the consequences of
this accumulation are the responsibility of each country. Hence addressing the
risks arising from rising emissions of GHGs must take the form of global
cooperation with commitments written into treaty obligations.
The growing
concern about climate risks led to a negotiating process aimed at deciding what
each nation should do and led to a global treaty, the UN Framework Convention
on Climate Change (UNFCCC) that was opened for signature in 1992. It entered
into force in 1994 and the first Conference of Parties (COP) was held in 1995
under the chairmanship of the then Environment Minister of Germany, Angela
Merkel.
Since the states had to act on impacts that
would take place only decades into the future, a process for building a
consensus on the underlying science and the facts and projections was
necessary. The five assessments that the IPCC has so far presented have
strengthened the scientific consensus on the facts and the projections, and
skepticism about the anthropogenic impact on climate is now limited to those
who have a commercial interest in fossil fuels. Even among those with a vested
interest there has been a rapid move away from questioning the reality of
climate change.
Initially the
focus in the negotiations was on the commitments of developed countries who
were largely responsible for the accumulation of the principal greenhouse
crash, carbon dioxide, in the decades since the start of the industrial
revolution. In the mid-Õ90s the Kyoto protocol was negotiated where the
developed countries, other than the largest emitter, USA, accepted modest
commitments to reduce their emissions. By the start of the millennium the
pressure for action shifted with the large increase in emissions from a
fast-growing China. The diplomatic process then shifted to diluting the distinction
between developed and developing countries and making commitments voluntary
national pledges rather than globally negotiated commitments. This led to the
Paris Agreement of 2015 limiting likely temperature increase to 20C,
with an aspirational goal of 1.50C included. All countries were required to
and filed nationally determined contributions (NDCs) to the global effort.
In 2018 the IPCC produced a report3 comparing the likely impact of a 1.5¼C
increase versus a 2¼C increase. The report said that limiting global warming to
1.5¼C would lead to lower mean temperature in most land and ocean regions,
fewer hot extremes in most inhabited regions, fewer heavy precipitation
incidents and lower the probability of drought and precipitation deficits in
some regions. A rate of sea level rise would be slower and enable greater
opportunities for adaptation in the human and ecological systems of small
islands, low-lying coastal areas and deltas. Limiting global warming to 1.5¡C
compared to 2¡C would lower the impacts on terrestrial, freshwater, and coastal
ecosystems. This report and the growing instances of extreme weather events
generated a sense of urgency prior to the November 2021 Glasgow meeting of the
Conference of Parties (COP) to the UN Framework Convention on Climate Change
(UNFCCC).
However, this
meeting has had limited impact on future projections
of temperature rise and its consequences. The outcome of Glasgow on commitments
for emission reduction relative to what was pledged after Paris in 2015 is
quite limited and amounts to about 3.3-4.7 billion tonnes of CO2 equivalent as against the reduction of 20-25 billion tonnes that is
required if we wish to contain temperature increase to the agreed Paris goal of
20C
or the aspirational goal of 1.50C. There were some sectoral pledges by
groups of countries at Glasgow on methane emission reduction, exiting from
coal-based power mostly beyond 2030, accelerating the move to zero emission
road vehicles and halting and reversing forest loss and land degradation by 2030.
A spate of announcements of target dates by
which a country would reduce its emissions of greenhouse gases to net-zero were
made before and during the Glasgow meeting. The qualification ÔnetÕ before
ÔzeroÕ implies that part of the transition to zero could be measures like
reforestation or carbon capture from emissions before it reaches the atmosphere
and then storing or converting it to some useful product. However, the time
path from now to the announced net-zero dates would still
lead to emissions that far exceed the limit for keeping the 50:50 chance of
temperature rises below 1.5¼C.
Focusing on six
major emitters, each of whom accounts for emissions over a billion tonnes a
year at present, USA, China and Russia would have to reduce their emissions to a
quarter, Japan to a third and the EU and UK to about half of the current
projection after taking account of the promises made. The target dates would
also have to be brought forward to well before 2050. India, which is one of the
six major emitters, would have to reduce its projected emissions to about
four-fifth of what it has promised. That goal, unlike the case for the other
five major emitters is quite achievable and so are the goals that it has
promised for 2030.4
Based on current trends and after taking all promises into account we are not on target to stay below 1.5¼C or even 2¼C. The negotiating process has now stretched over a quarter-century but has led only to limited progress in reducing climate risks. This can be seen in the increase in cumulative emissions from domestic production between 1990 and 2020 by 15 countries which are major emitters and account for over 80% of global emissions.
Except for the EU and Russia (where the fall is more due to the collapse of the old communist economy) none of the major emitters has restrained emission growth. These numbers bring out the very high growth of emissions in China and, to a lesser degree, in India. The last column compares the emissions that arise from consumption in a country to those that arise from production activities. This shows that the culpability of the developed world would look even worse if we were to correct for their transfer of emission intensive demands to other countries, which explains the lower consumption-based emissions in China, India and the fossil fuel exporters.
The root of the problem lies in the fact that the negotiating process is taking place in the classical diplomatic environment of sovereign countries bargaining for concessions from each other. Climate risks are shared global risks and we need a process that considers responsibility, both as culpability for past emissions which have caused the problem and as duty to use oneÕs capacity not just for oneself but also to help others who are vulnerable and less endowed with financial and technological capacity. This is what one would expect and get if a village were to be warned that it is likely to face a flood. But the global village lacks the ethos of joint responsibility.
There is a window of opportunity in the decisions taken at Glasgow asking countries to raise their commitments to a level that will bring us closer to the 1.50C path. But that will not happen unless the countries agree on principles of climate justice spelt out in terms of emission limits. Since even with a 1.5¼C increase there will be significant stress and higher weather risks, the global agreement must also include commitments by the rich nations who are more culpable and better placed financially and technologically to provide the required assistance to poorer, more vulnerable countries for mitigation and adaptation.
India is well placed to pursue this line of diplomacy as, amongst the major emitters, the gap between what it has promised to do and what it should under any reasonable principle of res-ponsibility is relatively small. It is also a country that is rated as the seventh most vulnerable and hence needs to push hard for substantial acceleration in mitigation activities. We have the capacity and the responsibility and must take this lead to save the lives of our children and grandchildren.
Footnotes:
1. Climate Change 2021, The Physical Science Basis: Summary for Policymakers. IPCC, August 2021.
2. Assessment of Climate Change over the Indian Region. Ministry of Earth Sciences, GOI, New Delhi, 2020.
3. Global Warming of 1.5¼C, IPCC, October 2018.
4. AuthorÕs calculations based on the promises made, the limits set by the IPCC for a 50:50 chance of staying below 1.5¼C and the principle that the utilization of this limit should be equal in per capita terms over the period 2020-2050.