On September 25, the Intergovernmental Panel on Climate Change (IPCC) released a special report on the oceans and cryosphere in a changing climate (SROCC). This new report is the first to exclusively address the impacts of a warming world on the world’s oceans and the cryosphere – the parts of Earth covered by glaciers, sea ice and permafrost.
(Note: One of the authors, Roxy Mathew Koll, is a lead author of the report.)
The report lists the emergence of extreme oceanic conditions in response to increasing carbon emissions – a catastrophe of human origin. These extremes are the oceanic counterparts of those on land and include marine heat waves, extreme El Niño oscillations and extremely severe cyclones. These events are new to our world and each of them has far-reaching impacts, especially on India and countries situated along the rim of the Indian Ocean.
Extreme El Niño oscillations
In 2015, the world experienced one of the strongest El Niño oscillations in modern instrumental history. The El Niño is a phenomenon associated with currents of warm water in the Pacific Ocean and generally occurs every two to seven years. The occurrence of an El Niño is characterised by warm ocean temperatures in the east Pacific, which then affect global weather.
India depends on the monsoons, and a moderate El Niño can render the monsoons deficient and erratic. When an extreme El Niño hit the world in 2015, India reeled with back-to-back droughts. Ethiopia and South Africa also experienced their worst droughts in 50 years. Together with severe heat-waves, the altered climate caused a 9-million-tonne deficit in the production of cereals, leaving more than 28 million people in need of humanitarian aid.
Such extreme El Niño events are likely to become more frequent in future, from one event every 20 years in the period 1891-1990 to one every 10 years by the end of the 21st century. Given what we have seen, such intensification is likely to immensely impact future monsoons, and in turn the economy of India specifically and South Asia generally.
Marine heat waves
The next monster is completely new: marine heat-waves. These are heat-waves over the ocean, much similar to that over the land, and they are the ocean’s erratic response to warmer waters. Worse, they often co-occur with extreme El Niño events.
Marine heat-waves hit sea life the hardest. Coral reefs occupy only 0.1% of the planet’s surface but are home to 25% of all animals found in the ocean. Corals can survive only within a specific range of temperatures, and so marine heat-waves are deadly to them and the complex ecosystems they have been known to support.
There are five reefs along the Indian coastline, off Andaman, Nicobar and Lakshadweep, and in the Gulfs of Mannar and Kutch; there are many more in the Indian Ocean itself, like around the Chagos archipelago. Recent marine heat-waves, including the one in 2016 that occurred together with a strong El Niño, mass-bleached these corals as well as severely adverse impacted aquaculture industries along the Indian Ocean’s rim.
Satellite observations have revealed that marine heat-waves likely doubled in frequency between 1982 and 2016, and that they have also become more resilient, more intense and more extensive. If humankind doesn’t cut its carbon emissions by significant amounts, a one-in-100-day event (with pre-industrial carbon dioxide levels) is projected to become a one-in-four-day event by at most 2050 and a one-in-two-day event by at most 2100.
Aside from heat-waves, the oceans have also been becoming warmer, more acidic and rising higher, even as their oxygen levels have been on the decline. The Indian Ocean is unusual in the sense that it has a relatively low oxygen content below the surface but has a relatively high surface production. Near-surface deoxygenation is bad news for such high productivity. These changes have accentuated coral-bleaching and have dealt a heavy blow on coastal wetlands, killing vegetation, wiping out habitats and changing community and ecosystem structures.
Marine heat-waves and coral bleaching events in 2015-2016. Photo: IPCC
The new IPCC report also points out a loss of coastal blue carbon habitats such as seagrasses, mangroves and marshes that sequester carbon. The fish catch in the Indian Ocean has also taken a hit due to ocean warming, as a result of changes in the way fish grow, reproduce and survive in newly dangerous waters.
Extremely severe cyclones
The third monster that has taken shape is the extremely severe cyclone. Changes in the ocean due to a heating world has increased the chances post-monsoon tropical cyclones can form over the Arabian Sea. In 2014, ‘Nilofar’ became the first such cyclone in the Arabian Sea to be recorded in the post-monsoon cyclone season. Though it did not make landfall, Nilofar produced heavy rainfall over India’s west coast.
The Indian Ocean has been warming rapidly, and these severe cyclones are projected to increase in number in a corresponding manner. We cannot neglect the possibility of these cyclones making landfall over the west coast of India in future and wreaking greater havoc.
Changing real-estate prices
Land-use planning for climate adaptation can aggravate social inequalities at the local level. For example, in Surat (India), Dhaka (Bangladesh), Manila (Philippines) and Jakarta (Indonesia), the purchase of homes at higher altitudes has increased property prices, displacing poorer people from these areas. The SROCC has noted the unequal impact of oceanic and cryosphere changes as a serious concern to be addressed with appropriate adaptation strategies consistent with the UN’s Sustainable Development Goals.
The IPCC report also presents Gujarat as an example of contrasting responses to this century’s preeminent crisis. The coastal city of Surat has been setting an example in adapting to climate change but Junagadh, another coastal district, has been finding it hard to move the needle.
Adaptation experiments in Surat have created important arenas in which governance actors and stakeholders can understand climate and development co-benefits, and test new ideas. In 2006, heavy rainfall resulted in a high discharge from the Ukai Dam that then flooded 75% of Surat. This in turn sent the incidence of gastrointestinal and vector-borne diseases skyrocketing. But Surat was able to act quickly because it had set up informal adaptation strategies independent of India’s national climate policy.
These strategies included moving industrial equipment to the upper levels of buildings; moving bank facilities to locations above previous older marks; compiling capital-asset databases for easing audits and insurance claims; and conducting local-level information, awareness and education programmes on the effects of vector-borne diseases.
The local government also maintains detailed records of each disaster, continuously collects and records from around the city, and conducts awareness campaigns about flooding, public health and other hazard-related vulnerabilities.
In 2012, the city advisory committee decided to institutionalise the adaptation planning process to sustain its momentum. In early 2013, the Surat Municipal Committee adopted climate change as one of the line-items to be included in their annual municipal budget. The committee earmarked Rs 2 crore (approx. $300,000) per year for climate adaptation and resilience-building.
Junagadh, however, hasn’t budged. The local fisheries industry has suffered a considerable decline in fish catch over this decade, together with changes in the seasonal occurrence and distribution of fish. People of the fishing community also lack access to clean drinking water, proper sanitation and healthcare facilities. Most of those surveyed by the IPCC lived in disaster-prone areas, with limited access to communication and waste management services, and with poor disaster management infrastructure.
The lack of an adaptive response in Junagadh could be due to a lower adaptive capacity and lower income compared to Surat. But a parallel lack of information and policy and administration support has been rendering it more and more vulnerable to natural calamities. As a result, fishers have been migrating to other parts of the country looking for work.
What now?
The IPCC report compiles the scientific evidence of climatic changes over the oceans. But other than examples of existing adaptive measures, IPCC reports tend not to recommend policies, leaving that to each country to decide for itself. So now that we have been alerted to these monsters of the open seas, it falls upon us to tame them, and not feign ignorance.
Compared to the US, whose national response to climate change has taken the backseat, leaving its states with the onus to respond appropriately, India is far ahead: it has developed and implemented mitigation and adaptation strategies, acknowledging that global heating is at its doorstep. In fact, the Centre has plowed ahead to set up a National Climate Change Action Plan and has promised to increase its already sizeable investments in renewable energy resources.
However, these investments haven’t been properly followed up, especially in the face of a large population. India can – and should – take up the climate crisis as an opportunity to lead other countries in the study and development of ocean-based renewable-energy resources and energy-efficient coastal and offshore infrastructure, and capitalise on its 5,000-km coastline for green transportation.
Roxy Mathew Koll is a climate scientist at the Indian Institute of Tropical Meteorology, Pune, and a lead author of the IPCC SROCC. Raghu Murtugudde is a professor of atmospheric and oceanic science and Earth system science at the University of Maryland. He is currently a visiting professor at IIT Bombay.