health, for instance. Academics tend to dismiss this as pseudoscience, which provides for a lot of heated arguments in the media and on public platforms.
What about the likely impact of mitigative measures that we are all exhorted to
take in the present so that our futures can be secured? Once again, we turn to an
IPCC “Summary for Policymakers”, which is all that the average reader is going to
have time to look at, this time of the Working Group III to the fifth IPCC report
(IPCC 2014b). This report, like the previous one cited, is prefaced by an equally
punctilious and precise statement of the basis of the uncertainty evaluations. The
report points out that “Effective mitigation will not be achieved if individual agents
advance their own interests independently”, which therefore demands “international
cooperation” (op. cit., p. 5). This immediately brings up “Issues of equity, justice,
and fairness”, because past contributions to global CO 2 have been different (we point
fingers at the industrialized countries), and current challenges (to reduce poverty and
increase incomes) and capacity to take up mitigation and adaptation measures also
differ (developing countries are at a disadvantage here). Further, “Climate policy
intersects with other societal goals creating the possibility of co-benefits”, which
suggests a stronger basis for undertaking climate action, and so on (ibid.).
An important part of the WG3 report is the information on the trends in greenhouse gases (GHGs) and their drivers (op. cit., p. 6 et seq.). We are told that total
anthropogenic GHG emissions grew by around 1.0 Gt CO 2 equivalent (a rate of
2.2 % per year) from 2000 to 2010, as against just 0.4 Gt per year (a rate of 1.3 %)
from 1970 to 2000. It may be noted that these are just year-to-year increases in the
annual GHG emissions; the actual emissions were of the order of 49 Gt in 2010 (the
highest recorded so far). The major contribution to the total GHG emission increase
is said to have come from CO 2 emissions from fossil fuel combustion and industrial
processes: in 2010, these contributed around 65 %, followed by other major sources
like CO 2 from forestry and other land use (11 %, with a very large uncertainty of the
order of ±50 %), methane (16 %), nitrous oxide (6.2 %), fluorinated gases covered by
the Kyoto Protocol (2.0 %) (op. cit., p. 7). Population and economic growth have
been the major drivers of increases in CO 2 emissions, and have outpaced emission
reductions from improvements in energy intensity (op. cit., p. 8).
What are the prognoses for global CO 2 levels? Without additional efforts at
mitigation, the growth in emissions is expected to “result in global mean surface
temperature increases in 2100 from 3.7 to 4.8 °C compared to pre-industrial levels”
disregarding climate uncertainty, with a threefold increase in CO 2 concentration
levels from around 430 ppm CO 2 eq in 2011 to 1300 ppm by 2100 (op. cit., p. 9).
The WG3 summary document goes on to discuss mitigation measures and their
possible costs, based on a collection of about 900 mitigation scenarios based on
integrated models, which would leave the CO 2 load by 2100 between 430 and
720 ppm (op. cit., p. 10). As can be imagined, it is not easy to comprehend all these
variations and their implications, but it appears that a concentration of around
250 ppm would be likely to keep temperature rise below 2 °C. Pledges made at
Cancun are said to be “broadly consistent with cost-effective scenarios that are
likely to keep temperature change below 3 °C” (p. 13). Lomborg (2001), however,
has earlier cautioned that any action to reduce emissions in the immediate future
30
P.J. Dilip Kumar
What about the likely impact of mitigative measures that we are all exhorted to
take in the present so that our futures can be secured? Once again, we turn to an
IPCC “Summary for Policymakers”, which is all that the average reader is going to
have time to look at, this time of the Working Group III to the fifth IPCC report
(IPCC 2014b). This report, like the previous one cited, is prefaced by an equally
punctilious and precise statement of the basis of the uncertainty evaluations. The
report points out that “Effective mitigation will not be achieved if individual agents
advance their own interests independently”, which therefore demands “international
cooperation” (op. cit., p. 5). This immediately brings up “Issues of equity, justice,
and fairness”, because past contributions to global CO 2 have been different (we point
fingers at the industrialized countries), and current challenges (to reduce poverty and
increase incomes) and capacity to take up mitigation and adaptation measures also
differ (developing countries are at a disadvantage here). Further, “Climate policy
intersects with other societal goals creating the possibility of co-benefits”, which
suggests a stronger basis for undertaking climate action, and so on (ibid.).
An important part of the WG3 report is the information on the trends in greenhouse gases (GHGs) and their drivers (op. cit., p. 6 et seq.). We are told that total
anthropogenic GHG emissions grew by around 1.0 Gt CO 2 equivalent (a rate of
2.2 % per year) from 2000 to 2010, as against just 0.4 Gt per year (a rate of 1.3 %)
from 1970 to 2000. It may be noted that these are just year-to-year increases in the
annual GHG emissions; the actual emissions were of the order of 49 Gt in 2010 (the
highest recorded so far). The major contribution to the total GHG emission increase
is said to have come from CO 2 emissions from fossil fuel combustion and industrial
processes: in 2010, these contributed around 65 %, followed by other major sources
like CO 2 from forestry and other land use (11 %, with a very large uncertainty of the
order of ±50 %), methane (16 %), nitrous oxide (6.2 %), fluorinated gases covered by
the Kyoto Protocol (2.0 %) (op. cit., p. 7). Population and economic growth have
been the major drivers of increases in CO 2 emissions, and have outpaced emission
reductions from improvements in energy intensity (op. cit., p. 8).
What are the prognoses for global CO 2 levels? Without additional efforts at
mitigation, the growth in emissions is expected to “result in global mean surface
temperature increases in 2100 from 3.7 to 4.8 °C compared to pre-industrial levels”
disregarding climate uncertainty, with a threefold increase in CO 2 concentration
levels from around 430 ppm CO 2 eq in 2011 to 1300 ppm by 2100 (op. cit., p. 9).
The WG3 summary document goes on to discuss mitigation measures and their
possible costs, based on a collection of about 900 mitigation scenarios based on
integrated models, which would leave the CO 2 load by 2100 between 430 and
720 ppm (op. cit., p. 10). As can be imagined, it is not easy to comprehend all these
variations and their implications, but it appears that a concentration of around
250 ppm would be likely to keep temperature rise below 2 °C. Pledges made at
Cancun are said to be “broadly consistent with cost-effective scenarios that are
likely to keep temperature change below 3 °C” (p. 13). Lomborg (2001), however,
has earlier cautioned that any action to reduce emissions in the immediate future
30
P.J. Dilip Kumar