Food security ’under threat’ as oceans suffer under climate change

Climate change is as much a problem for the oceans as it is for the atmosphere and land, the findings of the International Panel for Climate Change (IPCC) reveal.

Acidification of seawater as the oceans absorb almost a third of carbon dioxide emitted as a result of mankind’s activities was identified as one of the biggest problems, along with sea level rises, with implications for global food security.

The International Programme on the State of the Ocean (IPSO), a marine science organisation which provided data to the IPCC, said the climate change report released at a summit in Sweden reflects “exactly what we are seeing”, including widespread changes in the distribution of marine animals.

The IPCC’s report on the science of climate change found that sea levels have risen 19cm on average since 1901, the fastest rate in 2,000 years, and are expected to rise a further 26cm by the end of the century.

Upper levels of the oceans are warming by about 0.1C per decade while the temperatures in the deep acean will continue to rise for centuries, and acidification could make up to half of the Arctic ocean uninhabitable for shelled animals by 2050.

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Professor Alex Rogers, of the University of Oxford and IPSO scientific director, said: "The IPCC’s findings reflect exactly what we are seeing in the ocean: massive changes in the distribution of marine organisms and marine ecosystems globally.

“The IPCC”s focus on the ocean is long overdue and begins to reveal the extraordinary extent to which this critical Earth System is being impacted by climate change. There is no good news and no reason for optimism as our ocean continues to take the brunt of carbon absorption"

He added: “The combination of acidification, warming and deoxygenation that we are seeing - the so-called ’deadly trio’ - is unprecedented in the carbon record. It poses a serious threat not just to the ocean but to the Earth system services it supports"

The Global Ocean Commission, which is looking at the problems faced by the high seas and how they should be regulated, said the oceans were protecting the rest of the world from some of the impacts of climate change because of the quantity of carbon being absorbed.

“Without the immense capacity of the ocean to absorb heat and carbon dioxide, we would be experiencing much more severe climate change impacts than we see today,” said Trevor Manuel, Minister in the Presidency of South Africa and a Commission co-chairman.

“The clear implication is that we need to redouble our efforts to make the ocean resilient in the face of climate change and acidification. That means simple measures such as establishing marine reserves, but more fundamentally, tackling the gaps in governance of the international ocean that lies at the heart of many of its current issues.”

David Miliband, the former UK Foreign Secretary, a co-chair of the Commission and the CEO of the International Rescue Committee, said the changes in the ocean have frightening implications for food security.

“Disruption to ocean life results in less food for people – that’s the stark reality,” he said. “With nearly a billion hungry people in the world already, we need to take every option we can for increasing our food supply sustainably, rather than allowing climate change to compromise it.”

Achim Steiner, executive director of the United Nations Environment Programme, described the IPCC findings as a “dramatic reminder of both the significance, the pace, and also our ability to increasingly understand what is happening to our planet”.

He urged international action to tackle the problem: “This is not about ideology. This is not about self-interest. This is about the common interest of the international community, the planet, and ultimately our economies and society.”

Aware that climate change sceptics and deniers will seek to dismiss the IPCC’s findings as exaggerated, misleading or wrong, Prof Corinne Le Quéré, Director of the Tyndall Centre for Climate Change Research in the UK and one of the report’s lead authors, said that the weight of evidence for manmade climate change is overwhelming.

"This is not just another report, this is the scientific consensus reached by hundreds of scientists after careful consideration of all the available evidence,” she said.

“The human influence on climate change is clear and dominant. The atmosphere and oceans are warming, the snow cover is shrinking, the Arctic sea ice is melting, sea level is rising, the oceans are acidifying, and some extreme events have increased. CO2 emissions from burning fossil fuels need to substantial decrease to limit climate change"