Global warming mitigation by sulphur loading in the stratosphere: dependence of required emissions on allowable residual warming rate amg
А. В. Елисеев, А. В. Чернокульский, А. А. Карпенко, И. И. Мохов
Дата выхода публикации: | 2010-09-01 00:00:00.000000 |
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Язык: | английский |
Страницы: | 67-81 |
Страница пока не заполнена
Аннотация
An approach to mitigate global warming via sulphur loading
in the stratosphere (geoengineering) is studied, employing a large ensemble of
numerical experiments with the climate model of intermediate complexity IAP RAS
CM. The model is forced by the historical+SRES A1B anthropogenic greenhouse
gases+tropospheric sulphates scenario for 1860–2100 with additional sulphur
emissions in the stratosphere in the twenty-first century. Different ensemble
members are constructed by varying values of the parameters governing mass,
horizontal distribution and radiative forcing of the stratospheric sulphates.
It is obtained that, given a global loading of the sulphates in the
stratosphere, among those studied in this paper latitudinal distributions of
geoengineering aerosols, the most efficient one at the global basis is that
peaked between 50◦ N and 70◦ N and with a somewhat smaller bur-
den in the tropics. Uniform latitudinal distribution of stratospheric sulphates
is a little less efficient. Sulphur emissions in the stratosphere required to
stop the global temperature at the level corresponding to the mean value for
2000–2010 amount to more than 10 TgS/year in the year 2100. These emissions may
be reduced if some warming is allowed to occur in the twenty-first century. For
instance, if the global temperature trend Sg in every decade of this century is
limited not to exceed 0.10 K/decade (0.15 K/decade), geoengineering emissions
of 4–14 TgS/year (2–7 TgS/year) would be sufficient. Even if the global warming
is stopped, temperature changes in different regions still occur with a
magnitude up to 1 K. Their horizontal pattern depends on implied latitudinal
distribution of stratospheric sulphates. In addition, for the stabilised global
mean sur- face air temperature, global precipitation decreases by about 10%. If
geoengineering emissions are stopped after several decades of implementation,
their climatic effect is removed within a few decades. In this pe- riod,
surface air temperature may grow with a rate of several Kelvins per decade. The
results obtained with the IAP RAS CM are further interpreted employing a
globally averaged energy–balance climate model. With the latter model, an
analytical estimate for sulphate aerosol emissions in the stratosphere required
climate mitigation is obtained. It is shown that effective vertical
localisation of the imposed radiative forcing is important for geoengineering
efficiency.
Библиография
DOI: 10.1007/s00704-009-0198-6
# geoengineering# sulphur emissions# allowable warming rate# intermediate complexity global climate model
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