By the end of the twenty-first century
2 , average temperature over India is projected to rise
by approximately 4.4°C relative to the recent past (1976–2005 average
3 ) (Fig. 1), under the
RCP8.5 scenario (see Box 1).
Box 1: Description of future forcing scenarios
Projections by climate models of the Coupled Model Intercomparison Project Phase 5
(CMIP5) are based on multiple standardized forcing scenarios called Representative
Concentration Pathways (RCPs). Each scenario is a time series of emissions and concentrations of the full suite of GHGs, aerosols, and chemically active gases, as well as
LULC changes through the twenty-first century, characterized by the resulting Radiative
Forcing* in the year 2100 (IPCC 2013). The two most commonly analyzed scenarios in
this report are “RCP4.5” (an intermediate stabilization pathway that results in a
Radiative Forcing of 4.5 W/m
2 in 2100) and “RCP8.5” (a high concentration pathway
resulting in a Radiative Forcing of 8.5 W/m
2 in 2100).
*A measure of an imbalance in the Earth’s energy budget owing to natural (e.g.,
volcanic eruptions) or human-induced (e.g., GHG from fossil fuel combustion) changes.
Fig. 1 Best estimate and range in climate model projections of future changes in 1. Surface air temperature
over India (°C; bottom right panel), 2. Sea surface temperature of the tropical Indian Ocean (°C; bottom left
panel), 3. Surface air temperature over the Hindu Kush Himalayas (°C; top right panel), 4. Summer monsoon
precipitation over India (% change; centre panel), 5. Annual precipitation over the Hindu Kush Himalayas
(% change; top left panel). All the changes are computed relative to their climatological average over the
30-year period 1976–2005. Projected changes are reported for the middle and end of the 21st century under the
RCP4.5 and RCP8.5 scenarios (defined in Box 1). Details regarding the models and computations are discussed
in the respective chapters
2
Projections referring to the “middle of the 21st century” pertain to the climatological average over the period
2040–2069 and “end of the 21st century” to the climatological average over the period 2070–2099.
3
Unless otherwise noted, projected changes are reported w.r.t. this baseline period throughout the report.
xiv
Executive Summary
2 , average temperature over India is projected to rise
by approximately 4.4°C relative to the recent past (1976–2005 average
3 ) (Fig. 1), under the
RCP8.5 scenario (see Box 1).
Box 1: Description of future forcing scenarios
Projections by climate models of the Coupled Model Intercomparison Project Phase 5
(CMIP5) are based on multiple standardized forcing scenarios called Representative
Concentration Pathways (RCPs). Each scenario is a time series of emissions and concentrations of the full suite of GHGs, aerosols, and chemically active gases, as well as
LULC changes through the twenty-first century, characterized by the resulting Radiative
Forcing* in the year 2100 (IPCC 2013). The two most commonly analyzed scenarios in
this report are “RCP4.5” (an intermediate stabilization pathway that results in a
Radiative Forcing of 4.5 W/m
2 in 2100) and “RCP8.5” (a high concentration pathway
resulting in a Radiative Forcing of 8.5 W/m
2 in 2100).
*A measure of an imbalance in the Earth’s energy budget owing to natural (e.g.,
volcanic eruptions) or human-induced (e.g., GHG from fossil fuel combustion) changes.
Fig. 1 Best estimate and range in climate model projections of future changes in 1. Surface air temperature
over India (°C; bottom right panel), 2. Sea surface temperature of the tropical Indian Ocean (°C; bottom left
panel), 3. Surface air temperature over the Hindu Kush Himalayas (°C; top right panel), 4. Summer monsoon
precipitation over India (% change; centre panel), 5. Annual precipitation over the Hindu Kush Himalayas
(% change; top left panel). All the changes are computed relative to their climatological average over the
30-year period 1976–2005. Projected changes are reported for the middle and end of the 21st century under the
RCP4.5 and RCP8.5 scenarios (defined in Box 1). Details regarding the models and computations are discussed
in the respective chapters
2
Projections referring to the “middle of the 21st century” pertain to the climatological average over the period
2040–2069 and “end of the 21st century” to the climatological average over the period 2070–2099.
3
Unless otherwise noted, projected changes are reported w.r.t. this baseline period throughout the report.
xiv
Executive Summary