Mumbai: The impacts of climate change will continue to worsen, cautions the latest report of the United Nations Intergovernmental Panel on Climate Change (IPCC), and if drastic cuts in greenhouse gas emissions are further delayed, there will be an even smaller window of opportunity to secure a liveable, sustainable future on earth.

The report, released on February 28, is the fifth in a series of the Sixth Assessment Report cycle of the IPCC, the United Nations body for assessing the science related to climate change. Over 270 authors from 67 countries contributed in writing and reviewing this report. The earlier report, released in August 2021, had warned of an increase in global temperatures by more than 1.5°C on average over the next 20 years.

This report notes impacts and risks of climate change on cities, especially coastal ones. It also includes solutions, including how governments can adapt to climate change and develop the country in tandem.

"The report is important because it shows us that the scientific evidence is clearly saying that humans and ecosystems are already seeing the impacts of climate change. We definitely expect these risks to increase," said Chandni Singh, senior research consultant at the Indian Institute for Human Settlement, and one of the authors of this report. "The good news is that feasible and effective adaptation solutions exist. Many of these are already implemented, but the pace and scale of implementation has to rise significantly."

Climate change impact:

  • Even with low greenhouse gas emissions, that is global temperatures rise less than 1.6°C by 2100, 8% of today's farmland will become climatically unsuitable by 2100.
  • In Mumbai, by 2035, 27 million could be impacted by climate change, with high risk of floods and sea-level rise.
  • In Ahmedabad, 11 million people would be at a high risk of living in an urban heat island, with much higher temperatures than nearby areas.
  • At a global warming level of 2°C by 2100, up to 18% of all species on land will be at high risk of going extinct. If the world warms up to 4°C, every second plant or animal species will be threatened with extinction.
  • Children, 10 years or younger in the year 2020, are projected to experience a nearly four-fold increase in extreme events if global temperatures rise by 1.5°C by 2100, on average. Extreme weather will rise five-fold for a temperature increase of 3°C.
  • Globally, the percentage of the population exposed to deadly heat stress is projected to increase from 30% today to 48%-76% by the end of the century.
  • If the world warms more than 4°C by 2100, the number of days with climatically stressful conditions for outdoor workers will increase by up to 250 workdays per year in some parts of South Asia, resulting also in reduced food production and higher food prices.
  • Globally, 800 million to 3 billion people are projected to experience chronic water scarcity due to droughts at 2°C warming.

Cities at a much greater risk from climate change

By 2050, 70% of the world's population will live in urban areas, the IPCC report says. Cities are at much greater risk to extreme weather, like heat waves, that can aggravate air pollution and limit the functioning of critical infrastructure, such as transportation, water, sanitation and energy systems. Read our story on the vulnerability of India's critical infrastructure, including hospitals, roads, bridges and water treatment systems, to extreme weather events, and the need for 'climate-proof' and hazard-proof infrastructure.

"The likelihood of heat waves will increase across Asia, along with droughts in arid and semi-arid areas of West, Central and South Asia, floods in monsoon regions in South, Southeast and East Asia, and glacier melting in the Hindu Kush Himalaya region," as per an IPCC fact sheet on Asia. In addition, the fact sheet said that Asian countries could experience a 5% to 20% increase in drought conditions by the end of this century.

A billion South Asians could face water insecurity due to warming in the Himalayas, we had reported in July 2021. It will impact water availability in the Indus, Ganga and Brahmaputra basins, and megacities such as Delhi & Lahore will face the brunt, we had reported.

Biodiversity threatened by frequent extreme weather events

The more often ecosystems are impacted by extreme events and the more intense the event, the further they are pushed towards "tipping points", according to a set of frequently asked questions (FAQ) provided by the IPCC on the new report. Beyond this tipping point, abrupt, and in some cases, irreversible changes can occur – such as species going extinct. This risk increases steeply with rises in global temperature, as per the FAQs.

With global warming of around 4°C by 2100, which would result with very high greenhouse gas emissions, "mass mortalities and extinctions are expected that will irreversibly alter globally important areas, including those that host exceptionally rich biodiversity such as tropical coral reefs and cold-water kelp forests and the world's rainforests," the report said. "Even at lower levels of warming of 2°C or less, polar fauna (including fish, penguins, seals, and polar bears), tropical coral reefs and mangroves will be under serious threat."

Climate change could exacerbate hunger, disease, inequality

In Africa, where 40% of the population is under 15 years old, climate change could significantly increase the number of malnourished children by 1.4 million, because of the lack of food and under nutrition, according to the FAQs provided by the IPCC on the new report.

The spread of diseases due to climate change, especially infectious diseases, could undo decades of progress to control diseases, such as dengue fever, chikungunya, Zika, malaria and cholera, IndiaSpend reported in October 2021.

The IPCC report acknowledges that while individual livelihoods have been affected with changes in agricultural productivity, impact on human health, destruction of homes and loss of income, and other such impacts have exacerbated inequity across gender, caste, class and other socio-economic groups. For instance, women often experience greater workloads and stress during drought events, the report said, citing a 2021 study.

Similarly, in Mumbai, the houses of poorer families required repeated repairs to secure them against flood damage, and the cumulative cost of those repairs was a greater proportion of their income than for richer populations, the report said.

Adapt to climate change but be aware of maladaptation

Climate action has two parts: mitigation, which requires countries to cut back on fossil fuels, protect and expand forests, and promote clean infrastructure; and adaptation, which includes building critical infrastructure to deal with extreme climate events such as cyclonic storms, droughts and floods.

There is also increasing evidence of 'maladaptation'--actions that focus on risks in isolation, without taking into account the long term impacts of those actions. The report gives several examples, such as seawalls, that protect against coastline erosion in the short run, but can increase exposure to climate risks in the long run unless they are integrated into a long-term plan. Maladaptation can be minimised by "planning that accounts for the time it takes to adapt, the uncertainty about the rate and magnitude of climate risk and a wide range of potentially adverse consequences of adaptation actions."

Another example of maladaptation, the report said, is the Mumbai Coastal Road project, aimed at reducing flood risk and protecting against sea-level rise, which could potentially cause damages to intertidal fauna and flora and local fishing livelihoods.

The report talks about solutions that combine scientific and technological know-how with local and indegenious knowledge to facilitate climate resilient development. The report also pushes for safeguarding biodiversity and natural ecosystems. Ecosystems such as mangroves, wetlands, forests, and coral reefs act as natural shock absorbers that cushion the impacts of extreme climate events and promote community resilience, IndiaSpend reported in February 2022.

Also, while cities are hotspots of climate change impacts, they also provide the opportunity for climate action–such as green building, ensuring reliable supplies of clean water and renewable energy and sustainable transport infrastructure, Debra Roberts, co-chair of the IPCC Working Group said, as per a press release of the report.

For India, the IPCC report analysed two cities, and said that there has been "high" institutional and infrastructural progress in adapting and mitigating climate change in Ahmedabad, according to the Asia fact sheet of the report. There has been medium infrastructural progress in Mumbai, and little to no progress on the institutional and behavioural front.

For example, Ahmedabad has "pioneered preparedness for extreme temperatures and heat waves by developing annual Heat Action Plans," the report said, "building regulations to minimise trapping heat, advisories about managing heat stress, and instituting cool roofs policy."

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