There are some arguments which claim climate change doesn't exist or isn't such a big problem. There is no need to raise these arguments directly in a talk, but it is good to be prepared in case they come up as you may hear these from confused (or critical) people in the audience. Answering your opponents will greatly strengthen your case.
The first thing to stress is that almost all of these arguments originate in the 20 year long public relations campaign by the oil and coal industries to fight against international attempts to control greenhouse gas emissions. In the US this counter campaign has to date cost over £20 million.
Following from this point, people should remember that companies and governments have always "created" experts to justify their arguments. Tobacco companies have "scientists" to claim that nicotine is not addictive, asbestos companies have "doctors" to claim that asbestos does no lead to asbestosis of the lungs, and confectionery companies have "dentists" to claim that sugar does not lead to tooth decay. It’s a classic ploy by vested interests.
1. THE MAIN ARGUMENTS
"Scientists don't agree that there is global warming"
No one argues that greenhouse gas concentrations are going up extremely rapidly. No one argues that changing this will change the way the atmosphere behaves. The debate is about whether those changes will cause global warming- and whether they are the cause of the global temperature increases.
The strongest argument is the simple weight of expert opinion. Out of 2,000 scientists involved in the United Nations processes, around 10, sometimes called "climate skeptics", argue that there is no climate change or argue that burning fossil fuels is not a problem (some even argue both!). Names to look for include Richard Lindzen and Fred Singer. All 10 of these scientists are directly funded by the fossil fuel industry. So who do you believe?!
"Sunspots or changes in the earth's tilt cause climate change"
It's true that changes in solar output and tilt have historically had a major influence on climate change. But tilt changes very slowly and solar output has not changed sufficiently recently to explain the measured changes in global temperature. Again, the UN scientists are very clear that current changes are human created. Anyway, sunspots or no sunspots, when we change the gases in the atmosphere, we will change the way that it holds in the heat from the sun.
"10 years ago you warned of an ice age, now it's a heatwave! These are all scare tactics."
The concerns over an ice age were always a fringe theory 30 years ago- the science has moved forward and is now is extremely strong. Climate change is not predictable and extreme cold as well as heat is entirely possible if ocean currents change significantly.
"You said it would be hot -but it's freezing today / last winter. Where's the warming (ho ho)!"
Warming is measured across global averages and that local patterns will still vary greatly. "Warming" may be a misnomer on a local level as we're talking about increasingly extreme weather events (which may include extreme cold), interspersed with periods of more normal weather.
"So make your mind up- you don’t seem to have any idea of what’s going to happen"
We can be certain that this is a disastrous experiment which will lead to violent changes in the weather. The uncertainty is about how exactly this will effect local weather- we’re messing with something vital that we simply don’t understand. Scientific computer simulations are becoming far more accurate, though.
"Maybe with all this uncertainty, we should just wait and see and then take action"
There is a 40-100 year lag time before we feel the full effects of changes in the atmosphere. Politicians have been arguing for "waiting and seeing" for 20 years and the weather is already showing dramatic changes and what we’re experiencing now is the result of emissions in the 1960’s and before. We’d be mad to wait any further with such a long lead time. We’d just be dumping our indecision onto our grandchildren.
Also remember that we invest all the time in insurance against uncertainties. The government spend tens of billions of pounds a year on the armed forces to defend ourselves against outside risks that are impossible to estimate. At the moment the risk of climate change is far better established than the risk of enemy invasion!
"A bit of warming is just what we need in grey cold Britain"
Britain is not going to become the Costa Del Sol- and if it did every forest, garden and hedgerow would die. Yes it may get warmer, but droughts, floods, and extreme cold may also be part of the picture. The scientists predict hotter dryer summers but also wetter greyer winters with increased flooding and storms- so not much fun there. And there will be a terrible price to pay elsewhere - so we can't afford to be selfish.
"This is a left-wing/anarcho plot to overthrow capitalism/stop me enjoying my car etc."
It is nothing of the kind. Margaret Thatcher, John Major, the heads of British Petroleum and Shell Oil, the Confederation of British Industry, the Insurance industry all now acknowledge the threat and make strong statements of concern. Tony Blair calls it the "most serious" challenge of the 21st Century. If you really think these people are part of a global conspiracy, you're nuts. (Of course, none of them actually do anything, but that’s another story). In fact the only government leader who has denied the problem is George W Bush whose political campaign was largely funded by oil companies.
"It's the fault of the US."
The US is a huge burner of fossil fuels, twice as much per person as Britain and this is a serious problem. By all means we need to put pressure on the US. But we have a responsibility too to take a lead and sort out our own role. No-one ever wins a court case by arguing that there are bigger criminals about!
"It’s the fault of the Third World/overpopulation."
It's true that China and India also have rapidly increasing emissions and that within 25 years the Third World emissions will exceed those of the rich world. They will need to play a part in controlling emissions. None the less their emissions per person are still far far below ours (we emit ten times as much per person as an Indian). What is more, the greenhouse gases currently in the atmosphere are the result of the rich world’s emissions over the past 100 years, so we bear a historical responsibility.
"It’s the fault of cows farting."
Yes, cow farts do contain methane and play some role. But this is a very minor cause- and one often seized on by people trying to marginalise the issue. A far greater source of methane is from old landfill sites and coal mines.
2. THE FALSE SOLUTIONS
"We can all plant trees and it will be OK."
Tree planting is a red herring. Trees only soak up carbon dioxide whilst growing, but when they die/decay or are burnt they release it. So tree planting buys very little time. Tree planting cannot solve the scale of the problem and any effects it has are extremely temporary. What is more there are major environmental and social problems in the Third World associated with the seizure of land for exotic tree plantations — and let's face it, the Third World is where such large plantations would be planted.
There are lots of madcap "solutions" around- pumping carbon dioxide underground, setting up mirrors in space to reflect sunlight, seeding oceans with iron filings to encourage plankton. These projects are mostly funded by oil companies which have a strong interest in encouraging "business as usual". It’s very doubtful if they work, they are sticking plaster solutions at best.
"New car technology."
There is huge investment by car and oil companies into hydrogen, electric, and fuel cell cars. The big question is: where does the electricity or hydrogen come from? Most likely from fossil fuels. What is more, huge amounts of energy would still go into the steel, plastics, and manufacture of the cars. More efficient, less polluting cars will help, of course, but we still need to control and limit car use for many other reasons.
"I do my bit- I recycle."
"I do my bit- I recycle" is something people often say. But people need to know that recycling is a good thing to do for many reasons but is a very small part of the climate solution (composting food waste is the most useful component as it reduces methane production in landfill sites). People can do far more with simple measures in insulating and draught proofing their homes.
Rising Tide — Speaker Training Factsheet June 2001- www.risingtide.org.uk