Climate Change: adaptation and mitigation
Local climate action group Climate Karanga say we need to start thinking our about our future.
Donald Trump claims that climate change is a hoax. However, outside the White House, the overwhelming consensus of opinion, is that rapid climate change is happening and its effects are starting to become obvious. A graph of the temperature trends in Marlborough between 1922 and 2012 shows an increase from an average mean temperature of 9.5C to 11.5C.
At the same time, as the glaciers retreat and the polar ice caps melt, the sea level is rising. Globally, since around 1900, the sea level has risen by 20 centimetres. The rate of change is accelerating: a full quarter of that rise has occurred in the past 20 years. Official government forecasts, on which much local planning is based, envisage sea levels rising by 0.5 metres by the end of this century, with a worst case scenario of a 0.8 metre rise.
On the other hand, Professor Peter Barrett, of Victoria University, one of the world’s foremost Antarctic climatologists, believes that the increase will be between 2 and 2.5 metres and that by then, the rate of increase will be rapidly accelerating. Barrett believes that another leading climate scientist, James Hansen’s estimate of a 3 metre increase, is not impossible.
If and when such a point is reached, by the time children born this year qualify for their pensions, Marlborough will look quite different. Blenheim Post Office currently stands at just 3 metres above sea level. Sea levels are calculated from the mean between high and low tides. Around Marlborough the difference between high and low water is approximately 2 metres. A 3-metre rise would see the Blenheim Post Office ground floor 1 metre under water on the average high tide and have the contents of the oxidation ponds blocking State Highway 1.
So what is to be done? There are two strategies to follow. The first is ‘mitigation.’ These are steps individuals and their governments can take to reduce and even reverse the onset of climate change. The other is ‘adaptation.’ Adaptation entails adjusting policies to fit the changes in the environment that will inevitably follow the failure of attempts at mitigation.
At the 2015 Paris climate conference, the world’s leaders announced their decision to limit the rise in average global temperatures to just 2C, with the hope that they would be able to keep it below 1.5C. To achieve this goal, each country promised to follow a programme of mitigation and cut back its emissions of the greenhouse gases that are causing the temperature rise. New Zealand promised to reduce its greenhouse gas emissions to 30 per cent below its levels in 2005.
The government plans to achieve this goal by increasing the planting of forests to capture ambient carbon dioxide from the atmosphere and by paying taxpayer money to buy carbon credits from other countries, which are doing more than New Zealand to reduce their total emissions.
New Zealand’s big problem is that its economy is so reliant on dairy exports. Dairy farming produces large quantities of methane, which is a far more damaging greenhouse gas than the carbon dioxide produce by the burning of fossil fuels for transport. Were it not for the fact that most of New Zealand’s electricity generation is from carbon-neutral hydro, solar and wind, per capita, thanks to their livestock, New Zealanders would be one of the most polluting people on Earth.
Currently, if all nations who signed the Paris Accord keep to the promises they made, the global temperature rise could be limited to about 3C. This level would be insufficient to prevent the flooding of Blenheim. However, it is envisaged that the nations will meet to review the situation again in 2020 and make further cuts in their emissions.
Hope for the best while assuming the worst seems a sensible plan under the present situation. Marlburians should assume that globally, the governments of the world will fail to achieve either a 1.5C or 2C target in time to prevent radical changes to our environment and our economy. Indeed, the economy will have to alter dramatically if the necessary ‘mitigation’ measures to contain climate change are taken. It will alter willy-nilly and chaotically if they are not.
Assuming the worst, means adopting ‘adaptation’ policies that minimise the impact these changes have on Marlborough’s economy and its residents.
This monthly column will look in further detail at the province’s efforts at both mitigation and adaptation. In the meantime, those wanting to know more on the subject could look at the website of Marlborough’s own climate crisis site, climatekaranga.org.nz