Climatic change has occurred throughout history. Humans are affecting this natural cycle and the consequences may be catastrophic. Reducing this effect is the biggest challenge to ever face humanity, and the solutions will need to come from the minds of our generation.
One of the major difficulties faced by society in attempting to solve environmental problems – like climate change – is the inability to translate scientific evidence into effective policy responses. There will always be scientific uncertainty. This adds to political uncertainty, and inevitably policy inaction.
The uncertainty associated with a) the amount humans are contributing to climate change and b) the potential effects of this change, has been the main stalling block throughout the entire policy process. As recently as June last year, Don Brash stated he “still had to be convinced about climate change.”
Climate change sceptics are however, becoming less common, and there is growing demand for effective and precautionary policy responses based on the latest evidence, rather than taking a ‘wait and see’ approach.
We cannot wait for certainty in science, political consensus or miracle cures. The risk is too high, the option of ‘do nothing’, or ‘do just a bit’, are no longer viable. The buck stops with us.
The basics – what exactly is climate change?
The earth is a massive greenhouse in space. The glass of this greenhouse consists of certain atmospheric gases known as ‘greenhouse’ gases (GHGs), such as carbon dioxide (CO2) and methane (CH4). These gases, like the glass in a greenhouse, insulate the planet, and enable life to exist – without them the average earth temperature would be about -190C!
Over the past 300 years human society has become very efficient at producing GHGs – in particular CO2, which is released when fossil fuels such as oil and coal are combusted. While trees and plants use CO2 to grow, every year we are releasing 400 years worth of stored CO2, and the limited number of plants that exist on the planet today simply cannot soak it all up. So what happens to the excess gas? It remains in the atmosphere.
Concentrations of CO2 in the atmosphere have increased sharply over the last 300 years (see figure 1). In fact, recent studies published in the journal Science, found levels are now 27 percent higher than at any point in the last 650,000 years! By increasing GHG concentrations we are simply thickening the glass of the greenhouse, which – ask any gardener– will inevitably warm up the inside.
But we can’t let gardeners dictate policy can we? Never fear. There are always a few scientists near – over ten thousand of them in contributed studies to the international panel on climate change (IPCC). In 2001this independent body published some of the most striking illustrations of the potential impact humans are having on the earth’s climate. (see figure 2)
Conclusion: concentration of CO2 in the atmosphere and temperature on the planet are almost perfectly correlated – increasing CO2 (as we are) will lead to an increase in temperature. A 2004 workshop sponsored by the IPCC concluded if the atmospheric CO2 concentrations present in the 1700s doubled (to about 560ppm – nearer the lower end of predictions in graph above), it would result in a 30C rise in earth temperatures.
Great you say – Hawkes Bay temperatures in Wellington. Yes, perhaps, but this seemingly insignificant rise in temperatures will completely change the planet as we know it.
The effects will be felt across the planet
While scientific modelling of temperature and CO2 concentrations to predict future scenarios is useful, many of the sceptics on climate change manipulate the uncertainties associated with the calculations, and draw on past cases of failed predictions to illustrate the lack of credibility in the case. Unfortunately for these sceptics the warning signs are not only theoretical – change is upon us.
Sea level rise
Warmer temperatures melt landlocked ice and expand the water molecules in the sea. The great Greenland Ice Sheet, for example, has more than doubled its melt rate in the past decade. There have also been highly publicised satellite images of the collapse of the Antarctic Peninsula over the last few years – with the most recent data showing the region as a whole losing as much as 232 cubic km of ice each year. Increased melting equals greater volume of water in the sea, which equals higher sea levels. For most of the 20th century, sea levels have risen by 0.5 to 1mm a year. However this has recently increased to 3mm/year.
So what you say, what can a few millimetres a year do? There are three responses to this:
1) All those mm add up, especially with increasing temperatures. The IPCC predict sea levels will rise between 10cm and 80cm by the end of the century.
2) It takes time for ice to melt once it experiences warmer temperatures. Recent studies predict a 2.70C rise in temperatures will pass the threshold triggering the long term melting of the entire Greenland Ice Shelf – adding 6m to sea levels.
3) Most importantly, this melting ice can cause other, shorter term effects…
An abridged, de-Hollywoodised plot is this: Europe is warmer than it should be (compared to other regions of the world on the same latitude) due to an ocean current known as the gulf stream which brings warm water from the tropics across the Atlantic to north-western Europe. It then cools rapidly, sinks and returns to the tropics – much like a conveyer belt or escalator. Like any other machine it can shut down, and has done so in the past.
Evidence is also mounting that it this process is starting to slow down as we speak – largely due to huge quantities of freshwater flowing from the melting Greenland Ice Sheet. Freshwater is less dense and therefore restricts the saltwater from sinking and returning to the tropics to start the cycle again. Without its flow of warm waters, Europe would plunge into a localised severe long-term winter lasting many decades.
While certainly a very ‘extreme’ type of weather pattern, the European case highlights how climate change may not always result in warmer temperatures. Simple thermodynamics tell us that when a system (such as the greenhouse we call earth) is given more heat, the result is that there is simply more energy to dissipate. The energy is not dissipated evenly, it may be huge localised storms with large amounts of precipitation, or massive drought causing anticyclones. The key issue is the increased intensity.
Leading journals, such as Nature and Science, have published separate studies which have found a doubling of category 4-5 storms in the last 35 years, and show larger storms now occur 20-35% more frequently than smaller storms. Localised droughts are also becoming much more intense, especially in South East Asia and Amazonia, accompanied by large-scale forest fires.
We need look no further than our own back yard to witness extreme weather patterns. In the last few years there have been a number of ‘one in a hundred year’ storms, floods and droughts, such as those in the Manawatu, Hutt River and Marlborough regions respectively.
While these effects may not appear immediately threatening, what worries scientists most is the potential for the effects to add to the underlying problems. In systems theory these effects are known as positive feedback loops, and there are several examples in climate change.
By warming the planet we are i) increasing the decomposition rates of plants – releasing more methane, ii) reducing ice cover – increasing the amount of heat absorbed by the planet iii) warming the sea and reducing its density – potentially releasing stored methane on the ocean floor and iv) melting ice and exposing decomposing matter – also increasing atmospheric methane concentrations.
In simple language warming the planet equals more green house gasses equals thicker glass, equals warmer planet, equals more green house gasses and so on. While there is some buffering (by negative feedbacks such as increased cloud cover), we can easily reach a tipping point without realising it – where runaway climate change happens, with temperatures rising by 40C or more – a situation last recorded on the planet at the time of the dinosaurs.
At times this all sounds a bit of an ‘emission impossible’, I agree. However, it is a challenge that can be met, and with more widespread consensus among scientists it is now in our own hands and in the hands of our politicians to act.
What has been or can be done?
With mounting evidence, the world’s leaders decided that something needed to be done about climate change. In 1992 the United Nations developed a framework convention on climate change (UNFCCC), which spawned the Kyoto Protocol in 1997.
The Protocol binds developed countries to a combined 5% reduction of GHG below 1990 levels by 2012. This was not seen as the complete solution to climate change, but was an important first step. It has not however been signed by the worlds greatest polluter, the United States, which contributes 24% of global emissions.
The US instead opted to address climate change through an agreement with China, India, Australia, Japan and South Korea, which has the goal of aiding developing nation’s access to clean technology. Unfortunately ‘clean’ does not explicitly mean less GHGs. Some of the technology is low sulphur emitting coal power generators. This form of technology actually enhances warming by removing some of the particles that help inhibit sunlight – like the dust on the greenhouse windows.
It took until the G8 conference in July last year to finally get all the major world economies, including the US, to publicly agree that climate change exists, and that the impacts of doing nothing could be potentially catastrophic and extremely costly.
However, the benefits of doing something about it lie with future generations, while the current politicians need to make today’s society pay the price. This will cost votes. Therefore, dispite a growing awareness of the need to act, we still get very little political action – no more obvious than in good old ‘clean green New Zealand’.
The New Zealand Government has actively promoted the problems associated with climate change on the international policy agenda, and has discussed a range of domestic policy responses since the early 1990s. However, we still have no major policy, after recently dropping the proposed carbon tax. We are lagging behind many developed countries – even some states of non-Kyoto signatories Australia and the US.
While New Zealand’s emissions may not account for a huge component of global emissions (around 0.2%), our emissions per capita are one of the largest in the world and must be reduced. Firstly because we have to pay under Kyoto if we don’t, but more importantly because I hope we cherish our clean green environment enough not to be part of its future destruction.
While a number of smaller policies are being implemented, such as shifting to more biofuels, interest free loans for solar panels and investing more in public transport, by dropping the carbon tax we are lacking a major policy, and our emissions are continuing to grow.
Our Government needs to make a clear statement that as a country we are going to lead the world in climate change mitigation, following many European countries which have made strong commitments and have much stricter policies. But the Government will not act without the support of voters– the power lies in our hands.
What can WE do about it?
While motivating the Government to adopt stricter policies on climate change may seem difficult, it only takes a small number of potential voters to change a party’s position.
• Enrol in relevant university courses, eg : ENVI 114, 214, 314, ESCI 111, 201
• Go to interesting seminars/conferences: eg: Climate Change Conference, 28-29th March, Te Papa. Students only $70. Great international and domestic speakers such as PM Tony Blair, ex-chair of Shell Oil, and many acclaimed scientists and academics. http://www.vuw.ac.nz/sog/events/info-climate.aspx
• Watch out for the issue on news/tv/movies – ‘Climate Change Night at the Paramount’. Wednesday 29th, Paramount Theatre, Courtney Place, 6.30-10.30pm. Students only $7. Great movies, informal chat with an expert, free nibbles, time for drinks at the bar.
Change your ways:
• Catch more public transport/cycle rather than driving a car
• Buy more locally made food/products
• In the future invest in solar hot water heating or take advantage of Wellington’s wind and erect a small wind generator
• Turn off your appliances at the wall
• Reduce the amount of meat you eat (meat is highly emission intensive in production)
Solving climate change must not be seen as an insurmountable mountain, but a challenging climb that be accomplished with global cooperation and simple changes in individuals’ behaviour. It is our duty as an industrialised nation to take the lead on this climb and initially carry the packs of the developing world. The planning is over, we have been given the directions, the first steps have been taken, but the time is nigh for the real push forward. It is in our hands, and as Hillary once did, we must accept and meet this challenge. Would you like to be remembered as part of the generation that saved the world as we know it? I would.