The oceans are set to boil – BusinessLine

A 15-kilo tonne atom bomb fell on the Japanese city of Hiroshima on August 6, 1945. Imagine four such bombs falling somewhere or the other on the earth every single second! That would work out to some 126 million bombs every year. How much heat would 126 million Hiroshima-type atom bombs generate? That much heat energy, caused by sunlight hitting the earth, is prevented from dissipating away into space every year because of the wall of carbon dioxide and other greenhouse gases in the upper atmosphere, according to German climate scientist, Hans Schellnhuber. This has been happening for at least 30 years now.

Then how come we are still alive?

Thanks to the oceans. They have been absorbing 90 per cent of the heat trapped by the greenhouse gases. Alongside, they have been forced to suck up more CO2 these days than they have been doing for millions of years. The oceans, holding 97 per cent of the planets waters, have been protecting us from us.

But even good samaritans have their limits. The oceans are buckling under the burden and, unless the burden is removed or at least reduced, will collapse leaving humankind unprotected.

This message has been known for some time. But last week, a Special Report of the Intergovernmental Panel on Climate Change (IPCC) on Ocean and Cryosphere in a Changing Climate, has generated more evidence for what is already known, and has underscored a sense of urgency for action. The report has been prepared by 104 scientists drawn from 36 countries and is based on 6,981 studies and 30,000 comments enough credentials to establish that it is beyond reproach.

As the name suggests, the report looked (again) at the impact of global warming on the oceans and the frozen parts of the earth the polar regions and high mountains. The message, even if not new, is not amusing.

As Ko Barrett, an American climate expert and a Co-Chair of IPCC, observes, it is clear that the result of human actions is impacting the farthest corners of the earth, highest mountains and deepest seas.

Global oceans have been warming unabated since 1970 and have swallowed energy equivalent of at least 4 billion atom bombs of Hiroshima strength. A damning data-point is that in the 20th century, the oceans rose by 15 cm; by 2100, they would have risen by 1.1 metres, which is a very disastrous number.

As the oceans get warmer, they are also expanding and hence global mean sea levels are rising. Adding to the thermal expansion of water is the fresh water bounty coming from thawing permafrost, both in the polar regions and mountain ice caps, which is also creating a fresh water-sea water imbalance (stratification), causing further damage. And because the oceans are ingesting CO2, they are becoming acidic, killing food and oxygen for marine life and bleaching corals.

On the mountains, as the upper regions become warmer, plant and animal species are migrating up the slope, causing further disturbance in the ecosystem.

You might ask: Who bothers what will happen in distant 2100? But climate is not waiting in a corner with a cosh in hand for 2100 to come the effects are already upon us. Just one of the many examples of this is a phenomenon called The Blob (not part of the IPCC special report.) The Blob is the name given to a heat-wave phenomenon it occurs in oceans too that happened between 2013 and 2017 over 10 million sq km of waters in the Pacific, when the surface warmed over 3 degrees C than usual, resulting in salmon spawn shrinking to a seventh of normal and bringing the crabbing industry of California to its knees. The Blob is coming back again in 2019 and will keep coming back.

And the pity is, it is too late to reverse climate change now. We may, though, slow it down and take protective measures against the inevitable consequences of the damage done.

While much of all this is already known, the special report updates the knowledge. But more importantly, the report assesses, for the first time in the history of IPCC, local and indigenous knowledge systems to understand and adapt to climate change, says Anjal Prakash, Coordinating Lead Author for the report and Associate Professor, Regional Water Studies, TERI School of Advanced Studies, New Delhi.

The impact of changes in oceans and cryosphere is significant for India, a country with 7,500 km of coastline and therefore more vulnerable. Some 560 million people live in the nine littoral states and two union territories in India, of whom around 177 million live in the coastal regions. Mumbai, Chennai, Kolkata and Surat are severely threatened, the report says a warning to the local governments not to think of long-term projects along the coast.

Also, 10 major rivers originate in the Hindu Kush, Himalayas region, a region that has now come to be referred to as the third pole, and the basins of these 10 rivers are at risk. Major glaciers are melting, which are changing water regimes and changing weather patterns bring incessant rains, flooding downstream areas, says Prakash. We must understand that systems are interconnected, so we need greater co-operation amongst countries, he told BusinessLine.

Quoting another study, Prakash says that water consumption in the downstream areas of Indus, Ganga and Brahmaputra basins is projected to go up by 24, 42 and 107 per cent respectively during the current century. Water gap will increase due to socio-economic development and population rise, flood events will be more frequent and heat waves will be on the rise, he says.

Now that things have gone too far, the only option is to adapt. The mantra for solution is adapt, adapt and adapt, says Prakash. This involves first recognising the problems and taking protective measures for climate events that will surely happen such as making sure you put up no infrastructure on the coast, build resilient buildings with helipads on top, and plan for organised evacuation when necessary.

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The oceans are set to boil - BusinessLine