- Gradual wide-spread warming over northern India is projected by Regional Climate Models (RCM). Temperatures in the Ganges basin are expected to increase by an average of about 2 °C by 2050 and 4 °C by 2100, being more pronounced over mountainous areas.
- Annual total precipitation changes across northern India are less certain. Against a backdrop of considerable decadal variability, the slight increase in precipitation to 2050 indicated by the RCMs is unlikely to be significant.
- Regional differences in projected precipitation levels suggest a small decrease to be more likely towards the west of the Ganges basin by 2100, but an increase more likely towards the east.
- High intensity precipitation events are projected to increase in the Ganges basin. The intensity of flood events in the basin is expected to successively increase after 2050. Increased flooding intensity can result in enhanced sediment erosion, which will consequently reduce storage capacity of the reservoirs towards the end of the century.
- The expected continuation of glacier shrinkage in most parts of the Himalayan mountain ranges is confirmed by innovative modelling of glaciers at a large scale within RCMs, but with some increase in the western Himalaya and Karakoram.
- It is unlikely that the next decades will see dramatic changes in total runoff, but continued glacier recession will lead to changes in the seasonal pattern of runoff in upstream basins, with changes in both timing and amount of snow melt likely to affect flow in spring months, at times when other sources of runoff are scarce.
- Within India, several lakes located in Sikkim threaten downstream villages with Glacier Lake Outburst Floods (GLOFs). Glacier lakes studied in the states of Jammu and Kashmir and Himachal Pradesh are thought to present a minor risk to downstream regions.
- Drought conditions are expected to be exacerbated by 2050 as a result of higher temperatures and fewer rain days.
- Yields of existing varieties of both rice and wheat are projected to decline, with greater reductions in upstream regions, as negative impacts of higher temperatures offset positive effects of higher carbon dioxide concentrations. Downstream, in and around the Ganges delta, rice and wheat production might improve slightly, if precipitation increases.
- Stakeholders report increases in temperatures across the Ganges basin, nights becoming warmer, winters being shorter, greater variability in rainfall, and extreme events, mostly related to drought, becoming more
- Within the same state, stakeholder discussions showed commonality concerning perceived vulnerability across state, district, and community levels.
- In upstream regions, where stakeholders expect climate change to increase flood risk, adaptation measures to prevent flood damage are highly prioritized. In mid and downstream regions of the Ganges basin, stakeholders anticipate droughts and lowering of the water table, leading them to prioritize measures to maintain groundwater levels, and to develop water harvesting and water use efficiency.
- Rates of melt and accumulation of Himalayan glaciers are still not well understood. More research is needed on benchmark glaciers so as to better understand their dynamics, evolution, and response to climate change.
- The network of benchmark glaciers for sustained measurements should be extended to represent the large diversity of Himalayan glacier environments so as to allow better prediction of future meltwater yields.
- Using the identification of critical glacier lakes, lake monitoring and installation of early warning systems must now be developed.
- Further research is needed to understand regional and global mechanisms driving the Indian Monsoon to improve precipitation in climate models. Such understanding will also help in daily and seasonal forecasting of precipitation, useful for tackling floods and droughts alike.
- When limited in financial resources, invest either in regional climate models for spatial detail or in multiple general circulation models for spread in emission scenario outcomes.
- To support decision making on climate change adaptation, climate science information needs to be made available to stakeholders at all levels, in an understandable format and at a scale and detail, which is relevant to stakeholders.
- Robust climate adaptation decision making, needs to account for both the uncertainty in future climate projections and for natural climate variability, which may lead to shortterm variation in climate.
- At present, adaptation measures in India are planned at national and state level, not taking into account the physical boundaries of water systems. To prevent adverse effects in other parts of the river basin, planning should be tailor-made at the river basin scale.
- To increase resilience, adaptation plans should be made locally specific. Enabling the exchange of case studies and good practices will facilitate the development of robust solutions.
- Large scale water storage for agriculture is not a viable option for mid and downstream of the Ganges basin, partly due to topography. Focus should rather be on more local distributed storage. That would also help in inducing natural recharge to replenish the ever reducing groundwater.
- Recent scientific developments have led to an increase in skill in long-term forecasting on the seasonal, annual, and decadal scales. These forecasts may provide important information to decision makers. Further development of these forecasting skills should be encouraged.
- To enable quantification of cost and benefit analysis of adaptation options, more empirical research is needed integrating participatory qualitative methods and quantitative model-based outcomes.
- Common knowledge could be increased by supporting comparison, evaluation, and monitoring of approaches.
- A platform for the exchange of information and good practices regarding climate adaptation is recommended.
- Making bio-physical and socio economic data available to the research community will greatly decrease the uncertainty in research outcomes and consequently increase the value of these research results for society.
- Results from the HighNoon project could be transferred to other countries trying to achieve the Millennium Development and Sustainability Goals by Green Economic Growth.
Read the HighNoon Science and Policy Brief - Adaptation to Climate Change in the Ganges Basin, Northern India