Last reviewed 6 March 2013
The long-term implications for life on a warming planet are that both global climate change and very local health and safety risks could pose equal threats. Is the UK planning to live with the consequences? Jon Herbert reports.
Mention climate change and most people think immediately of rising sea levels, desolate droughts, destructive floods and failed harvests. But global warming is also about real human costs to communities, homes and individuals.
As an example, there are growing concerns that a rapid spread of infectious diseases and food poisoning could be as harmful to future life, health and safety as the raw physical power of recent super-storms experienced worldwide.
Any attempt to fight back poses two fundamental questions. First, can the rise in atmospheric greenhouse gas levels – manmade or natural – behind global warming be stopped or reversed? And if it is too late to turn back the clock, could we at least slow down the rate of acceleration?
Second, can we learn to live with the consequences of unstoppable warming and find innovative ways to adapt to our new unstable circumstances?
The Climate Change Committee (CCC) Adaptation Sub-Committee (ASC) has been assessing exactly this. In two previous reports it studied the impact, cost and dangers of climate change, plus prospects for mitigating measures and potential for adaption.
Now, in a third report, the ASC looks at the results of applying the generic adaption risk assessment toolkit it created at a national level to two of the largest risks out of more than 700 potential impacts emerging from the UK’s first Climate Change Risk Assessment (CCRA) — flooding and water scarcity.
But firstly, a glimpse at the broader picture shows why building new “resilience” at many levels is becoming so important.
What drives planners and policy-makers is the fear, almost inevitably bound to become a reality, that things can only get worse.
The idea that world warming is gathering speed has been discussed for several decades. However, the links and permutations between energy flows, the mass movement of hot and cold air, sea temperatures, currents and “weather” is proving more complex and harder to predict than expected.
Several factors are now clear. The first is that no matter what humans do to reverse the impact of industrial emissions, global warming is here to stay. We have put enough pollution into the atmosphere historically to maintain a “snowballing” greenhouse blanketing effect that will continue to push up worldwide temperatures ad infinitum.
A second linked to this is that feedback mechanisms have been under-rated. A warmer world will force yet more carbon dioxide to be released from the seas, soils, decaying leaf mould and trapped methane escaping from beneath melting tundra.
The intimate degree to which changing weather and climate phenomena around the planet are proving to be very closely linked has also come as a surprise. It is now thought that Arctic ice melting allows sunlight to warm polar seas, which in turn affects seasonal air flows that could be displacing the jet stream and normal weather patterns experienced over North America, Europe and Asia.
In part, this may have enhanced the destructive power of Hurricane Sandy, itself a super-storm caused by warming tropical waters. Typhoons over the Philippines, freak storms in the American Mid-West and unusually wet Russian weather hitting grain harvests may all be similarly related. These could have a direct impact on each one of us.
A healthy mind and body in a healthy world
The Chartered Institute of Environmental Health (CIEH) believes that extreme weather, climate change and health and safety are intricately connected with more far-reaching human well-being implications than normally realised.
It is concerned that public health is being challenged to the extent of “putting at risk the very pillars of life; clean water, sanitation, air quality and food” and points out that climate change mitigation strategies are almost synonymous with health impacts.
The CIEH warns that heat waves, food and water shortages, infectious diseases and the forced effect of population movements will put at risk the old, poor, sick and young in Europe, but particularly in developing nations.
Historically, the UK has concentrated on preventing cold-related deaths. We can now expect more heat-related deaths, the CIEH believes. Skin diseases, infections and endocrine disorders such as diabetes are exacerbated by heat. Heat tolerance is also impaired by the use of some antidepressants.
One estimation suggests that these hidden aspects of a warmer climate could raise the current level of heat-related deaths from some 800 annually to 2800 in 2050. The CIEH points out that while “extreme high temperature episodes” normally come once every 350 years, the frequency could rise to once every five to six years by mid-century.
However, UK cold-related deaths could fall from around 80,000 annually as fatalities associated with coronary thrombosis and respiratory infections decrease to around 60,000 by 2050.
Another concern is a rise in food poisoning associated with heat, particularly linked to imported infections. Because micro-organisms survive for longer in hot conditions and are exacerbated by dirty water and poor sanitation, there is a greater potential for disease spread.
Changes to hydrology and water ecosystems will favour some infections. Heavy rainfall that increases surface water turbidity is known to lead to higher bacteria and pathogen counts. This could pose a problem for water treatment works that abstract from rivers.
Conversely, slower river flow rates could increase pathogen concentrations, albeit that greater exposure to sunlight has an anti-microbial effect.
In developing countries, cholera increases have been related to climate change, leading to fears for an eighth cholera pandemic, possibly boosted by increased numbers of international travellers.
Even the mental health of climate victims is considered. Adults with flooded houses have shown a four-fold increase in psychological stress. Ear ache, gastroenteritis and skin rashes also increase with flood events.
Meanwhile, high winds cause a surprising number of injuries as a result of people falling. Head injuries, fractures, bruising, lacerations and eye injuries all increase. There are also dangers from falling chimneys, loose tiles from roofs and wall collapses.
One area of good news is that air pollution is likely to fall with rising temperatures as particulates, oxides of nitrogen and sulphur dioxide levels drop when less fuel is burned for heating.
Aromatic hydrocarbon levels associated with cancer could also fall. However, warmer weather would raise the level of pollen known to exacerbate asthma and hay fever.
Flood and water scarcity
By using a series of national indicators to focus on preparations for adaption to the future impact of flooding and water scarcity in the UK, the ASC has made some surprising findings.
It favours a twin-track mitigation and adaptation approach and says that with active preparation for climate change, the number of English properties at risk of flooding could be reduced to just 25%.
Government and local authorities should be more robust in planning, it warns, noting that development grew faster on floodplains than anywhere else in the last decade. Many development projects are well protected by community defences. Nevertheless, one in seven properties are now at risk and specific site design features should be used to improve resilience to flooding.
Figures also show that floodplain developments in England grew by 12% in the last 10 years compared to 7% elsewhere. The majority were protected by raised ground and floor levels, plus safe exit evacuation routes. In the last three years, flood defence investments have reduced risks to 182,000 homes.
However, the ASC warns that the present “build and protect” approach to floodplain development will leave a legacy of rising protection costs as climate change bites deeper. Existing properties also need new defence investments, plus support for the social and economic consequences of more frequent unavoidable flooding. Current investment levels will not keep pace with the growing flood threat.
Some 3.6 million homes and businesses now face some form of flood risk. Circa 10% of power stations, water treatment works, fire, police and ambulance stations are currently based on floodplains.
Climate change could actually double the number of properties at the higher significant risk level by 2035 without firm action, the ASC predicts. By the 2080s, without intervention the current total could rise to between 630,000 and 1.2 million buildings.
The Environment Agency estimates that investment needs to grow by £20 million above inflation every year to keep risk levels constant as climate change and deteriorating existing flood defences begin to make their mark.
However, the approval process is less than transparent — the Environment Agency only knows in about 65% of cases whether its advice has been followed. There is also a real need to assess the potential for taking growth away from floodplains.
It is clear that simple steps such as door guards and air-brick covers could help more remote, low-population areas that are hard to protect with flood defences. However, present uptake rates are some 20 to 35 times lower than they need to be if all 200,000 to 330,000 properties that could benefit are to be covered.
Surface water flows
Good surface water management to control flood flows is an important aspect of adaptation and will be the ASC’s next task. The paving and tarmacing of urban areas has made this more important, particularly if climate change brings more rain. From 2001 to 2011, the total garden area paved over increased from 28% to 48%.
Sustainable drainage, plus the use of roads and pathways as emergency flood channels, can help to shield vulnerable properties from the worst downpours.
The Government and water companies should also step up efficient water use through metering and pricing mechanisms to safeguard against future water scarcities, especially where supplies are stretched, suggests the CEIF.
This would have a treble benefit, it says: consumers would save money; infrastructure investment costs would be deferred or reduced; and less abstraction would also limit damage to the environment. Personal water consumption by individuals could be cut from 145 to 130 litres daily by 2035, the CEIF adds. This would go further than current plans and could halve the shortfall predicted from climate change and population growth.
England has been hit by drought once in every seven years over recent decades. Because the extent and timing of annual and seasonal changes is uncertain, water companies estimate that without action nearly half of the country’s water resources could be run dry during droughts by 2020.
The CCRA assessment shows that the supply-demand mismatch could range from almost nothing to three billion litres a day. The central estimate is 1.2 billion litres, or 7% of existing supply. Current water company plans propose to cut any deficit by 1.4 billion litres by 2035. Half of their effort will go into improving supply, the rest into reducing consumer demand and limiting leakage.
In 2010, leaks accounted for 22% of total water supply, primarily as a result of cold winters and pipe bursts. By reducing this to 20% through investments over the next 25 years, water companies calculate that a further 240 million litres could be saved daily.
Studying other impacts
The ASC is now applying its toolkit to other key climate risks and opportunities seen as CCRA priorities. These will include agriculture, forestry and the natural environment, how heat and cold impact human health and energy use. The work will also look at business supply chains and consumer demand.
A second risk assessment will also build on experience from the first in a five-year cycle.