What is Climate Change?
"Climate Change" means dramatic changes in long-term weather patterns.
The average temperature of the air and sea around the world has increased noticeably, The last ten years have been the hottest on record. The global temperature is now hotter than over the past 1000 years, and very likely hotter than any time in the past 100,000 years.
This "global warming" causes rainfall and weather patterns to change, resulting in long droughts, severe storms and bushfires. These consequences along with rising sea levels, loss of coastal settlements and agricultural land , affect us all, now and future generations, locally and globally.
Climate scientists, scientific societies and governments agree that climate change is happening and will become greater during this century. The changes are subtle, build up and can accelerate till it will not be possible to reverse them.
The Good NewsThe good news is, we can make a difference before it is too late - if we inform ourselves and take action.
What causes climate change?
The Earth’s temperature is the result of a balance between heat from the sun and outgoing heat from the Earth. Gases in the Earth’s atmosphere trap some of the outgoing heat. Because this effect acts like a greenhouse these are called “greenhouse gas-es”. The most important greenhouse gas is carbon dioxide (CO2). Carbon dioxide in the atmosphere is necessary for plants to grow. But through burning fossil fuels (coal, oil and gas) for energy and for producing cement and steel, and through changes in land use, it has risen to dangerous levels during the past 200 years (by 30% since 1880, most since 1970). We now put thirty billion tonnes of CO2 into the atmosphere annually. This extra CO2 traps more of the sun’s heat and raises the Earth’s temperature.
The main sources of CO2 emissions in Australia are electricity generation (50%), agriculture (15%) and transport (13%). Unless we significantly change the way we produce and use energy, we will get more temperature rise, threatening life on Earth. Photo image courtesy of image creator Dan and freedigitalphotos.
What are the effects — now and later?
Global warming’s effects on day-to-day weather are very gradual but are starting to be noticed now. So far much of the extra heat has been stored in the oceans and absorbed by polar ice and glaciers as they melt. Each decade since the 1940s has been warmer than the previous one. The North Pole was ice free for a part of 2007. We are now seeing more destructive cyclones, floods, bushfires and other extreme weather around the world. Sea levels are rising because of warmer seas and melting ice sheets. Storm surges and high tides are becoming more damaging, threatening many coastlines, in-cluding Australia, and people in low lying countries will be threatened and some will become refugees.
Negative health effects of climate change are al-ready noticeable, especially through more heat waves and increased pollution. Malaria, dengue and yellow fever are extending south from the tropics, and new diseases may develop. Bleaching of coral reefs and loss of biodiversity are tragic. Life in the oceans is threatened through acidification.
Are there reasons to doubt it?
Scepticism is important for scientific thinking. Climate change “deniers” (so-called sceptics of climate change) include some scientists who are usually in fields other than climate science. Sceptics present arguments ranging from rejection of all aspects of climate science, to criticisms of detail. Some repre-sent interests such as the fossil fuel industries.
Over 2,500 of the world’s scientists study climate change. Their conclusions are reviewed and tested by other scientists from government, industry and universities. The United Nations Intergovernmental Panel on Climate Change (IPCC) summarises and reports on their work. All 183 UN member govern-ments can review and challenge the results.
Human-induced climate change is now established as a fact. Disagreements are about the urgency and action that need to be taken, or about a few specific predictions (see http://www.skepticalscience.com/). The challenge is to make the necessary changes happen.
Why take action now?
Destructive effects of climate change are happening faster than expected. Our individual and collective health and survival are at stake. If greenhouse gas emissions keep increasing and do not start to decline before 2020 we may reach a “tipping point” when it is too late to turn things around. As more ice melts we will reach a point where no ice will return to moderate Earth’s temperature and climate.
Most scientists believe that a “safe” climate requires a temperature rise of less than 2oC from 1900 levels. We have had a 0.8oC rise already. They estimate that world emissions need to be reduced by 20–50% by 2020. Staying at current levels of emissions is not safe. We also need CO2 reduction strategies to get atmospheric CO2 levels down to no more than 350 parts per million (ppm) of the atmosphere. It is at 390 ppm today and rising.
Will change be expensive?
The earlier we act, the easier it will be and the less it will cost. Official studies (such as the Garnaut and Stern Reports) have shown that effective action on climate change will cost less than 1% of our GDP over the next 40 years. The cost of inaction will be greater than the cost of action. Using energy more wisely reduces both cost and emissions. This is rela-tively easy to achieve, particularly in housing, use of buildings, industrial processes and transport.
What can government & industry do?
Australia is the world’s worst greenhouse gas polluting nation per person, emitting about ten times the UN’s worldwide target necessary to avoid dangerous climate change. In spite of our small population we are the 14th largest emitter of CO2 in the world. Government and industry produce about 80% of the greenhouse gas in Australia. As the driest inhabited continent, Australia has much to lose from climate change. It is in our own interest to set a good example for other nations.
Government needs to:
• charge or tax those who create large CO2 emissions
• support alternative technologies
• offer incentives for industry to reduce emissions and develop renewable energy
• stop giving money to polluting industries, and
• reduce its own large emissions.
Industry needs to:
• cooperate with government in setting a realistic price on carbon
• initiate investment in new technologies and processes that are efficient, climate friendly and support environmental and social sustainability
• inform and encourage its own members to reduce emissions.
Workers in fossil fuel dependent industries are being retrained for the production of renewable energy and non-polluting technologies. By growing these new industries, we will be on the leading edge of the new technologies for energy production. There will be thousands more clean green jobs in the new sustainable economy than in the outmoded fossil fuel economy.
Other resources to consult:
Australian Conservation Foundation, http://www.acfonline.org.au
CSIRO + Bureau of Meteorology, State of the Climate, http://www.csiro.au/resources/State-of-the-Climate.html
Australian Greenhouse Office, http://www.greenhouse.gov.au
Nature Conservation Council, http://www.nccnsw.org.au
Total Environment Centre, http://www.tec.org.au
Union of Concerned Scientists, http://www.ucsusa.org
World Wildlife Fund, http://www.wwf.org.au
Worldwatch Institute, http://www.worldwatch.org
What can you do?
Each one of us can:
• reduce electricity use at home—less heating, airconditioning and lighting; buy efficient appliances and turn them off at the wall
• walk, cycle and use public transport
• reduce, reuse, repair, recycle
• tell your local, state and federal members what you think and what needs to be done about climate change
• get informed, change what you can and join with others for action
• Talk to friends and neighbours about what is necessary and possible now and later
• buy from companies seriously committed to sustainability, and
• shop, buy and waste less — every dollar spent produces on average ½ kilogram of CO2.
