Climate change having ‘widespread and consequential’ global impact

On every continent and in the world’s seas and oceans, the effects of human-induced climate change can be felt.

Coral reefs, described as the UAE’s most diverse marine ecosystems, are also vulnerable to higher temperatures and water acidification, according to the Climate Change 2014 report. Antonie Robertson / The National
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Climate change has arrived and is already having “widespread and consequential” effects on the world around us.

That is perhaps the starkest message from the Intergovernmental Panel on Climate Change’s (IPCC) recently published report, Climate Change 2014: Impacts, Adaptation, and Vulnerability.

On every continent and in the world’s seas and oceans too, the effects of human-induced climate change are being felt, according to the report.

Sea temperatures are rising, killing coral, permafrost is melting, plants and animals – land and marine – are moving to cope with changes in temperature, and agriculture is being affected.

In the face of such effects, the report should “jolt people into action”, said Rajendra Pachauri, the chairman of the IPCC, when the research was released.

Average temperature rises of the magnitude considered in the report, of between 2°C and 4°C, could have severe impacts in the Arabian Gulf region.

Aside from the effects on agriculture, a climate that is already difficult to cope with would become even more inhospitable for people: the report notes that “extreme heat” poses the risk of “mortality, morbidity and other harms”.

The possibility of more frequent extreme weather events is another threat to lives. The IPCC says climate change poses “the risk of severe harm due to inland flooding and limited coping and adaptive capacities of large urban populations”. These problems were seen graphically in 2009 when the Saudi Arabian city of Jeddah suffered what were described as its worst floods in 27 years, causing the loss of more than 120 lives.

Although the IPCC states that the effects of climate change are already being felt, the Abu Dhabi-based International Renewable Energy Agency (Irena) said this week that temperature rises could be limited if sufficient investments in renewable energy were made.

To prevent average temperature rises by 2100 exceeding 2°C above pre-industrial levels, carbon dioxide (CO2) concentrations in the atmosphere, currently 398 parts per million (ppm), must be kept below 450ppm, according to Irena.

The organisation reported the world’s annual CO2 emissions are currently set to rise from 30 gigatonnes (Gt) in 2010 to 41.4Gt in 2030. But if renewables’ share of the global energy mix is quadrupled, 8.6Gt would be cut from the projected 2030 emissions total. When combined with improved energy efficiency, Irena said global emissions could fall to 25.5Gt by 2030.

“The latest report by the IPCC reconfirms that averting catastrophic climate change is possible if we act now. But we need to act decisively. Renewable energy, in combination with energy efficiency, provides the most affordable and technologically mature path to bring about the necessary change,” said Adnan Amin, Irena director general, at the opening of the World Green Economy Summit in Dubai.

Agriculture

While in temperate regions, many crop yields are likely to grow as carbon dioxide levels and global mean temperatures increase, in the UAE and other parts of the Gulf, the opposite is likely to be the case. The IPCC report notes that in West Asia, which includes the Gulf region, “upward temperature trends are notable and robust in recent decades” and that further warming is “very likely”.

It states that many parts of Asia are likely to see a decline in agricultural productivity, and this is likely to have suffered significantly by about 2050.

To cope with the changing climatic conditions, the organisation suggests more drought-resistant crops will have to be grown. Efforts to develop varieties that can cope with severe water shortages and extreme heat stress are already taking place in the UAE. Examples include quinoa, a cereal-like crop from South America that is tolerant of very high temperatures and the high salt levels that come with extreme temperatures and water stress. Studies have been undertaken in Dubai to determine how suitable this crop would be for UAE farmers.

A key measure highlighted in previous studies, such as a 2009 Environment Agency Abu Dhabi (EAD) report, Climate Change: Impacts, Vulnerability and Adaptation, is installing drainage infrastructure at the same time as irrigation systems are put in, because this reduces salt build-up.

Studies have noted that any loss of land area as a result of rising sea levels could severely impact agricultural productivity in the Gulf region, with low-lying areas, such as parts of the UAE and Bahrain, for example, especially vulnerable.

Aside from crops grown for human consumption, the IPCC report also notes that the distribution of tree species is likely to change as a result of climate change, with the ideal habitat for many species likely to move farther from the equator. In the Gulf region, and the UAE in particular, vast efforts have been undertaken to plant trees and turn barren desert green, with 120 million trees plus 25 million date palms having been planted. But EAD noted previously that the challenges of climate change, with higher temperatures and increasing water shortages, mean that serious consideration will have to be given as to whether such efforts can be continued, not at least because they account for four fifths of the emirate’s water use.

Marine ecosystems and productivity

The report suggests climate change could have a devastating effect on fishing in the Arabian Gulf over the next five decades. While some parts of the oceans are predicted to produce increases in catches of 50 per cent or more, in the Gulf the opposite is likely, with a drop of more than 50 per cent in the maximum potential catch predicted.

A key factor causing a reduction in fisheries habitats, according to previous studies, is likely to be the effects of climate change on seagrass, which provides a habitat for fish as well as being an important food source for large marine creatures such as dugongs. If sea levels rise as predicted, the light available for seagrass is likely to be reduced, while higher temperatures are also likely to adversely affect the plants.

With current rates of thermal expansion of the oceans suggesting sea levels could rise 50cm by the end of the century, in the Gulf, according to 2002 research cited by EAD, that could translate into a drop in seagrass productivity of one third or more because of reduced light levels – with potentially significant knock-on effects for fish and larger marine life.

Many marine habitats are severely threatened by rising sea levels, according to the IPCC, with increasing levels of acidity – the result of an atmosphere where CO2 levels are higher – exacerbating the effects of rising temperatures.

Habitats such as mangroves and salt marshes, both of which are found in the UAE and elsewhere in the Gulf region and which have a higher diversity of species than many other locally found habitats, are likely to decline, unless they are able to move inland. According to the earlier EAD report, the UAE’s sabkha areas, which are flat, salty desert habitats with little growing on them, are also likely to move inland. Experts will have to pinpoint “habitat migration corridors” to allow mangroves to shift inland as sea levels rise.

Coral reefs, described as the UAE’s most diverse marine ecosystems, are also vulnerable to higher temperatures and water acidification.

Sea levels

In low-lying coastal zones, the IPCC notes there is a “risk of death, injury, ill-health or disrupted livelihoods” as a result of “storm surges, coastal flooding and sea-level rise”. Such effects could well affect lower-lying parts of the UAE and other Gulf countries.

“Vulnerabilities of industry, infrastructure, settlements and society to climate change are generally greater in certain high-risk locations, particularly coastal and riverine areas,” the report said.

Nations with extensive coastlines, which include all of the Gulf States, face risks to their “territorial integrity” as a result of sea-level rises, the IPCC report said.

A previous University of Arizona study cited by EAD in its 2009 report indicated that much of the UAE coastline would be vulnerable to sea-level rises, including most of downtown Abu Dhabi, while other studies have indicated that the UAE coastline is far more likely to be affected than the Omani coastline, for example. A mean sea-level rise of three metres would lead to Abu Dhabi losing 800 square kilometres of its area.

According to Professor David Holland, a climate specialist at New York University Abu Dhabi, a sea-level increase of between one and three metres could happen within the next 100 to 200 years if much of the water currently locked up as ice is released as a result of melting caused by warmer currents. He said previous events in New York, such as Hurricane Sandy in 2012, show that when storms, high tides and sea-level rises go together, there can be severe consequences for coastal areas. And if such effects can hit New York, he suggests, coastal cities such as Abu Dhabi, among others, could also face challenges.

“If you raise sea levels by several feet, if you walk along [Abu Dhabi] the Corniche, all that would be under water. You build a wall or you go inland. New York has found that out,” he said.

EAD suggested work should be carried out so that in the short term, coastal infrastructure is able to cope with sea-level rises of between one and three metres, because extremely high-tide events are more likely as storms become more frequent and stronger.

Areas such as the sabkha that can act as “natural buffers” against seawater inundation are likely to struggle to cope with significant sea-level rises.

Water resources

Globally, water scarcity is set to become an increasing challenge in the coming decades as populations grow, according to the IPCC.

The organisation warns that climate change will “reduce renewable surface water and groundwater resources significantly in most dry subtropical regions, exacerbating competition for water among sectors”.

Many Arab countries are already facing these difficulties, with a United Nations survey from earlier this year, Arab World: Atlas of a Changing Environment, having indicated that19 of the 21 members of the Arab League have water scarcity as a key issue.

However, in its earlier report, EAD noted that climate change would only have a marginal impact on water resources in the UAE, which lies on the border between tropical and subtropical, since the country already has severely limited supplies, with a paucity of renewable freshwater and “no reliable, perennial surface water resources”. In simple terms, the country has so little rainfall and such limited water resources that any changes to current weather patterns are unlikely to have a severe impact.

A more important factor determining the extent to which water shortages become a problem is demand, with the heavy population increases and economic growth seen in the UAE and other Gulf states in recent years causing requirements to increase sharply.

In the UAE and many of its neighbours, the focus is on desalination. The country has the capacity to desalinate more than 1.7 billion cubic metres of water annually, the highest figure in the world after only Saudi Arabia. Desalination capacity in the Emirates is continuing to expand, with the vast Dh10 billion M Station in Jebel Ali having opened a year ago and with work taking place to extend the Emirates Sembcorp Water & Power Company facility in Fujairah.

Yet, despite the biggest threat to water resources coming from population growth, there are clear ways in which climate-change-induced alterations to the climate could affect the country’s ecology.

EAD noted in its earlier report that many of the UAE’s ecosystems, those that occur naturally and those that are managed, are not resistant to drought and that they could be vulnerable as a result of changes in rainfall patterns and rises in temperatures. Wadis are among the areas most at risk.

dbardsley@thenational.ae