India needs customised climate projections rather than IPCC reports: study

The Global South, particularly South Asia, is far more vulnerable to climate change than the Global North and at the same time, lacks the capacity to deal with global warming scenarios unlike the more affluent and better equipped developed countries. This inequity has been a matter of discourse around loss and damage and mitigation and adaptation funding.

A new study highlights inconsistencies and contradictions in climate projections for Global South countries in the Intergovernmental Panel for Climate Change (IPCC) reports – a major pitfall in framing effective adaptation policies.  Most countries in the Global South, in the absence of their own national or regional climate assessments, draw guidance from IPCC’s periodic assessments to come up with effective mitigation and adaptation policies.

The study reviews all six assessment reports (FAR to AR6) from IPCC, the UN agency that is responsible for advancing scientific knowledge on climate change. It concludes that the distillation of these assessments to the national or regional scale has several uncertainties. The paper highlights two scenarios particularly — annual temperature and precipitation projections in South Asia; the two climatic variables that play influential roles in policy framing.

Accurate projections needed for better policies

Across all reports, the surface air temperature over the South Asian region is projected to increase with an increase in extreme events such as heatwaves and extreme rainfall. The study, by a team of multi-country researchers, notes that there are considerable inconsistencies in the magnitude of temperature change projected and more disparities in the spatial distribution in all the reports. In the fifth assessment report (AR5), for instance, the magnitude of temperature change projections ranges from 0.5 °C to 6 °C under different emissions scenarios outlined in the IPCC reports.

The study points out that the regional distribution of temperature changes in the AR4, the IPCC’s fourth assessment report in 2007, indicates that the northern part of South Asia is warming more than the southern part, with the most intense warming (~4 °C) over the northwestern region (Afghanistan, Pakistan and northwest India), moderate warming (~3 °C) over central India, and modest warming (~2 °C) over the Indian peninsula and Myanmar. However, the projected change in temperature is spatially homogeneous over the region in the more recent AR5 and AR6, with much smaller regional variations than reported in the assessment reports preceding them. Similar inconsistencies are being pointed out in the case of precipitation projections as well.

“Inconsistency in climate projections from six generations of IPCC assessments for most of the Global South is found to be a major roadblock for effective policy making for the region. This has exacerbated the many challenges the Global South faces in adapting to climate change” said Saroj K. Mishra, a professor of atmospheric science and project investigator of DST Centre of Excellence in Climate Modeling at Indian Institute of Technology Delhi (IITD).

Mishra shared that the inconsistency in projections stems partially from uncertainties due to parameterisation in the climate models. Since most of the model development efforts are done in the countries in the Global North, better climate simulations are observed over these countries due to many underlying factors relating to model developments, he said.

Need to amp up modelling capacities, regional assessments

The paper suggests solutions like modelling with better resolution, such as kilometre-scale modelling, for example, as “it can improve the representation of complex topographies and other surface properties, mesoscale processes and associated feedbacks, and moist convection and gravity wave drag”. Mishra said that kilometre-scale modelling is practiced in affluent countries. Since it requires huge infrastructural advances and better computational resources, lower-income countries are not able to adopt such models. The paper suggests a collective effort between less affluent countries at a continental scale through multi-governmental engagements in building their own modelling capacities.

Since it is a time-consuming process, the paper recommends the Global South nations bolster regional climate modelling efforts in the interim, which can enhance the reliability of country-scale future projections.

The Indian Institute of Technology, Delhi is working towards the customisation of a global model for high-resolution treatment of the Indian region. Given the similarities among nations across the Global South, the nations can share insights from these efforts. “We analysed 50 climate models. We chose one that is the best for the region and are working on customising it. This can later be used by other countries in this region,” Mishra informed.

Other short-term suggestions proposed by the authors of the paper include more frequent regional climate assessments by governments. While India is making progress in regional assessments, the intermittent and irregular nature of these reports are not helpful, note the researchers. The paper points out that there was a decade-long gap between two regional assessment reports which, considering the rapid change of climate and the concurrent rapid advancements of technological capabilities, is a long gap. Another pitfall is that “these assessments are not yet mandated and regulated by law, which exempts the concerned government agencies from being accountable,” notes the paper.

Some experts are of the opinion that the current study’s emphasis on better climate modelling and finer computational resources, though scientifically relevant, is not of top most priority in the larger scheme of things. T. Jayaraman, senior fellow, climate change at M.S. Swaminathan Research Foundation, who is not related to the study, observed that the importance of computer modelling should not get out of proportion. “What we need regionally is better and finer weather forecasting, both s​hort and medium range. We need to improve our last mile delivery of forecast information as well as better adaptation mechanisms and socio-economic growth to deal with future global warming. From the Global North, we need adaptation finance in the form of grants, not loans.” he said.

Read more: IPCC report shows a greater need for increased climate action

Banner image: Floods in Laos in 2019. Some climate scientists in the Global South say that lower income countries should come up with more localised climate projections to develop better adaptation policies. Photo by Basile Morin/Wikimedia Commons.