Climate change science and impacts

Where can I find accurate information on climate science?

A really good source of information is at www.skepticalscience.com , from John Cook, Climate Communication Fellow at University of Queensland. See especially the arguments pages, including responses to over 100 of the most common climate denial lines, all based on peer reviewed science.

There is also good information from the Climate Council, which is just getting going to replace the Climate Commission. The Climate Commission was established by Labor in Government to provide the public with information, but which was sacked by Tony Abbott’s government.

Just out in February 2014 are FAQ and other information jointly from the US National Academy of Sciences and the Royal Society.

Is climate change happening, and are human emissions causing it?

Yes, and yes. Climate scientists are 95% sure, to rigorous scientific standards, and getting even more certain as even more evidence keeps coming.

The International Panel on Climate Change reports give details. The Climate Council has an excellent summary of the most recent (5th) IPCC report on the science.

As Labor’s Mark Dreyfus has said in Parliament:

There is no more reason for policymakers, ministers or anyone in Australia to be now challenging the science of climate change, as people, unfortunately, are being encouraged to do—led by our current Prime Minister.

Even Rupert Murdoch has said that “climate change poses clear, catastrophic threats” to our society (although you wouldn’t know it from his tabloids).

Do people in Australia accept that climate change is happening?

A CSIRO survey released in early 2014 showed 81% of people in Australia agree the climate is changing. A majority (although a lower number) accept that humans are causing it. Even Tony Abbott (sometimes) says he believes it.

Only 8% of Australians think the climate isn’t changing, with slightly more than that in the “don’t know” column.

People who deny climate change is happening are out on the fringe of public opinion as well out of step with the science. Oddly, though, the survey showed that the 8% think nearly half of Australia agrees with them. Maybe they just get their science from the shock jocks. And maybe this is why they feel okay campaigning against action on climate change.

There’s way more climate denial in the Australian media (including places like talkback radio and the Murdoch press) and in Australian Parliaments than there is in Australian public opinion, let alone among scientists. Much of the denial you hear originates with paid “think tanks,” like the Institute of Public Affairs or their equivalents in the USA, who won’t disclose where they get their money.

These FAQ are meant to help with answers when you see or hear people getting it wrong.

Hasn’t the climate always changed?

Science tells us that Earth’s climate has changed over millions of years, due to things like the very slow drift of continents. The Earth has seen species come and go with this.

But we are talking here about big and rapid changes during our own human lifetimes, and in our children’s lifetimes. Still think it’s to the point that the climate has changed before?

Aren’t CO2 and other greenhouse gases a tiny part of the atmosphere, and aren’t human emissions even smaller?

This is another favourite of people who take their science from Alan Jones instead of from the CSIRO. But the fact that CO2 is only a small proportion of Earth’s total atmosphere, is exactly why changes in the amount of CO2 being emitted since the Industrial Revolution are able to have a significant effect on this proportion.

As Margaret Thatcher said in 1989: “none of us would be here but for the greenhouse effect. It gives us the moist atmosphere which sustains life on earth. We need the greenhouse effect—but only in the right proportions”. She said in the same speech: “We are seeing a vast increase in the amount of carbon dioxide reaching the atmosphere.”

Since pre-industrial times, the concentration of CO2 in the earth’s atmosphere has increased by 40 per cent, with around 500 billion additional tonnes of the gas pumped into the atmosphere over that same period. From studying things like Antarctic ice cores, scientists can tell that this is the highest atmospheric concentration of CO2 in at least 800,000 years.

Isn’t it just the sun?

No. Solar radiation reaching Earth does vary slightly (mainly from small, predictable variations in the Earth’s orbit, as well as from sunspots). But for the last 35 years, we have experienced reduction in solar radiation reaching Earth, at the same time as we’ve had above average temperatures (in the atmosphere and still more in the oceans).

The solar energy that really counts here, is the solar energy from millions of years ago that’s stored in the fossil fuels we’ve been burning, and the solar energy from our own time that we need to use more of right now.

Aren’t volcanoes and bushfires more important sources of CO2 than human emissions?

No. Humans emit more than 100 times as much greenhouse gases as volcanoes do. Volcanos have had very little impact on the last 40 years of global warming and if anything their clouds may have had a slight cooling effect. And global warming will make bushfires more likely to happen, more likely to happen earlier in the season, and more likely to be severe.

Didn’t global warming stop in 1998 (or some other year after that)?

No. Climate deniers confidently repeat this as if it were an established fact (Tony Abbott said it on the Alan Jones show in December 2009), but no. The World Bureau of Meteorology says no.

As Professor Ross Garnaut said in the 2011 update to his Report:

There is a statistically significant warming trend, and it did not end in 1998 or in any other year.”

Every year since 1976 has been above average. If you were born in 1976 or later, you’ve never lived in a below average year. 2013 was Australia’s hottest since records began (confirmed by Australia’s Bureau of Meteorology) and the world’s 4th hottest.

Doesn’t a cold winter in America prove there’s no global warming?

No. Extreme weather of all kinds is actually made more likely by global warming.

For the 2013-14 North American winter, the “polar vortex” of very cold air has strayed south. This seems to be because global warming has reduced the air pressure differences that we can usually rely on to keep this vortex at home near the North Pole. Look up the short video from President Obama’s chief scientific advisor explaining it.

A ship with some scientists got stuck in Antarctic sea ice this summer. Doesn’t that prove there’s no global warming?

No. Any more than the fact that there’s ice in your freezer proves what the temperature in the whole house is doing.

If anything, the sea ice having drifted in unusual ways might actually be a result of climate change, although they aren’t sure about that.

What we can be sure of is that the claims that this event disproves global warming (by the Murdoch press and by former Liberal staffers writing in supposedly better papers), tell you far more about the people behind the stories than they do about climate change.

Some scientists somewhere sent something in emails to someone a while ago. Doesn’t that prove there’s no global warming?

No. People who hacked into scientists’ emails in the UK, for the story they want you to believe, are about as trustworthy as the people associated with Rupert Murdoch’s papers in the UK who have been caught out for hacking the phones of royal family members, and celebrities, and victims of crime.

The scientists whose emails were hacked have been cleared of any wrongdoing. Yet somehow this is meant to prove that scientists worldwide, including NASA, and the CSIRO, and the Weather Bureau, are all part of a conspiracy to invent or exaggerate global warming? Right.

It’s all too scary to think about. Can’t we just not talk about global warming?

Wouldn’t it be nice if climate change really was all made up, and we didn’t have to do anything about it? But shutting our eyes and talking loudly about something else won’t make this one go away.

As Labor’s Bill Shorten has said, we don’t elect leaders just to look the other way when hard issues come along.

Why should we trust scientists when they’re paid to promote global warming theory?

Let’s be honest: the attack on science is ridiculous and shameful. And much of it is made (honestly or not) by people who are paid to make it – or by the worst Tea Party types in Tony Abbott’s own party.

There is just no evidence for a worldwide conspiracy by scientists to invent or exaggerate global warming. And people who are paid to make these attacks, or the anonymous billionaires in the US who have been shown to be funding climate denial through trusts and foundations, are not in an independent and trustworthy position themselves, least of all to accuse other people of being part of a paid conspiracy. Don’t believe them.

NASA says that they are certain global warming is happening. Only the real fringe thinks they faked all those moon landings too!

Here’s what Malcolm Turnbull said:

Those of us who do not believe the CSIRO is part of an international Green conspiracy to undermine Western civilisation, or do not believe that leading scientists like Will Steffen are subversives, should not be afraid to speak out, and loudly, on behalf of our scientists and our science. We must not allow ourselves to be deluded on this issue.

Are the seas really rising? I haven’t seen it in the years I’ve been going to the beach …

Yes, the seas are rising. Measurements over the last century showed slow but steady rises. This has been too slow to see happening, but it has still been serious. Unfortunately, newer predictions, including more accurate satellite measurements, and allowing for melting glaciers and icecaps, are for faster and worse sea level rises.

The World Meteorological Organisation advises that sea levels are now rising about twice as fast as they did on average across the 20th century. If emissions continue to increase unabated, sea level could rise by around 1 m by 2100. Sustained warming could eventually lead to the loss of the entire Greenland ice sheet, with a rise in sea level of up to 7 metres. And release of the methane currently trapped in the Arctic permafrost could lead to far worse results still.

Is a bit of sea level rise all that serious?

Yes. Even a small rise in sea levels will give a higher base for tides, let alone for storms or cyclones. Some countries – and some of Australia’s coasts – don’t have much more than a metre above sea level. Kakadu’s freshwater wetlands and the tourist industry based on them are very vulnerable, for example. Local governments like Hobart plan on the basis that 3 metres of freeboard above average sea level is needed before an area can be said to be above the effects of storm surges and king tides.

And the actual sea level rise from unchecked global warming could be far, far worse.

Why would global warming make the seas rise?

Water expands as it heats (from 4oC upwards). And the oceans are absorbing more heat as global warming occurs. We know now that over 90% of global warming is going into the oceans. On top of that, glaciers and ice sheets are melting and sliding into the sea.

Does it matter all that much if the seas are getting more acidic?

Yes. CO2 dissolving in the oceans is making the oceans more acidic. This threatens many of the food chains that marine life and ultimately we humans depend on. Increased acidity affects the ability of shellfish to make shells, to take one example.

Is climate change causing more and worse hurricanes?

Overall, yes. While we can’t say any individual storm was caused by global warming, it’s basic physics that more energy in weather systems can be expected to produce more severe weather events.

Hurricanes draw their energy from heat in the ocean. Warmer oceans will produce more and worse hurricanes. And higher sea levels will mean more damage caused by storm surges.

Can’t we just adapt, the way humans have adapted to changes over history?

Rapid climate change – like the one from the asteroid hit that seems to have wiped out the dinosaurs, or like rapid global warming from our own industrial emissions – is not something easy to adapt to. And it’s really not something that we want to see in our and our children’s lifetimes.

Our climate is changing faster now than it has in the thousands of years of human civilisation.

We will have no choice but to adapt to some level of climate change. The IPCC says we probably can’t avoid around 2oC of warming on average. That will be serious enough. But the more global warming there is, the harder and more expensive it will be to adapt.

To take just one example, most cities around the world have been built just metres above nearby seas, and the amount of sea level rise will depend on the amount of global warming.

Won’t more CO2 just make more plants grow?

No. Climate change presents big threats to farmers in Australia and around the world. For example, it is changing the rainfall and other seasonal patterns that farmers depend on. And lots of the extra CO2 is making the oceans more acid, which threatens food sources there. Only complete ratbags think or say we need more CO2.

Isn’t it too late to worry about changes that happened because of the industrial revolution?

This isn’t mainly about what people did in the 19th century, before almost anyone knew about the greenhouse effect or global warming. Half of all fossil fuels burned, ever, have been burned since 1985.

What we do, right now and from now, matters. This is why the Climate Commission (before Tony Abbott tried to silence it by cutting off its funds) called its report “The critical decade”.

If it’s too late to stop climate change, why should we bother doing anything?

The more global warming there is, the harder and more expensive it will be to adapt. The International Energy Agency has estimated that each year of delay from here would cost an additional $500 billion. The sooner we take effective action to reduce the threat, the more hardship and expense we can avoid into the future.

Adaptation will be important too, but we need to apply our abilities for innovation to preventing all the global warming we can, not just trying to mop up afterwards and adapt to whatever comes along.

Aren’t there lots of environmental issues besides climate change?

Yes, of course. But climate change and other most other environmental issues are linked.

For example, climate change threatens biodiversity in many environments, including in Australia. Climate change will put rivers in Australia like the Murray-Darling, and native plant and animal habitats, under even more pressure. And many other environmental threats – like threats to forests – also carry climate risks.

Here’s a reminder of what long term environmental activist Peter Garrett said in support of Labor’s clean energy legislation:

In all the environmental campaigns I have been involved in, none is so important—nor is there any environmental issue as important—as tackling dangerous climate change.

As the World Wildlife Fund said on World Wildlife Day 2014, if you care about protecting wildlife you have to care about climate change.

How is forest protection important to climate change?

Land clearing in itself releases CO2. Also, older forests with bigger trees absorb and hold more CO2 than newer plantations. So loss of forests will make climate change worse.

What gases apart from CO2 are important?

As well as CO2 , there are other important greenhouse gases where we need to take action, including methane (from animal waste and coal and gas emissions ) and various refrigerant gases. The Clean Energy Package addressed these – Tony Abbott’s team opposed action on these too.

Do sources of emissions besides coal fired power stations matter?

Yes. Different kinds of fossil fuels (and biofuels too, like ethanol or wood) all emit CO2 when we burn them, whether we use them for transport, heating or power. We also need to take into account emissions from farming, land clearing and mining (including incidental emissions of methane from extracting natural gas or coal, as well as emissions from power for mining equipment).

What can I do when I see and hear climate myths?

If it’s someone you know, give them better information. If it’s someone in the media or a public position, challenge them, or let someone know who can. If you need more information, contact your local ALP member or candidate; or one of the environment group contacts listed on this site.

The International Panel on Climate Change (IPCC)

What is the International Panel on Climate Change?

The IPCC was established by the UN Environment Programme and the World Meteorological Organisation in 1988, and endorsed by the UN General Assembly the same year. It is an intergovernmental body open to all countries which are members of the UN. Australia has been a member from the outset.

Isn’t the IPCC exaggerating the risks?

No. Numerous expert papers have documented how the IPCC is actually more likely to be underestimating the risks.

The IPCC has avoided making predictions on those climate change issues where it considers not enough evidence is in yet. For example, warming and sea level rise could be made far worse (think dozens of metres), quite quickly, if the permafrost in Arctic regions melts and releases its methane – but the IPCC hasn’t made predictions on that yet because it isn’t satisfied yet.

Where can I find the IPCC’s reports?

The website of the International Panel on Climate Change is at http://www.ipcc.ch/ . The IPCC publishes regular Assessment Reports on the state of knowledge of climate change as well as more specialised information.

Climate Change 2007 was the IPCC’s Fourth Assessment Report. In common with earlier reports the Fifth Assessment report will be released in 4 phases (from September 2013 to October 2014): Climate change 2013: The physical science basis (now available); Impacts, Adaptation and Vulnerability (due March 2014); Mitigation of Climate Change (due April 2014); and Synthesis Report (due October 2014).

Where can I find a summary of the latest IPCC reports?

The Climate Council has an excellent summary of the most recent (5th) report on the science.

The IPPC itself has a Summary for Policymakers of the first section of the Fifth Assessment Report released, on the physical science of climate change.

Key findings from this Summary for Policy Makers are copied below.

Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased

Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850

Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010

Over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent

The rate of sea level rise since the mid-19th century has been larger than the mean rate during the previous two millennia

The atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years. Carbon dioxide concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions. The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification

Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of CO2 since 1750

Human influence on the climate system is clear. This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiative forcing, observed warming, and understanding of the climate system.

Climate models have improved since the 4thAssessment Report. Models reproduce observed continental-scale surface temperature patterns and trends over many decades, including the more rapid warming since the mid-20th century and the cooling immediately following large volcanic eruptions

It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.

Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.

The IPCC goes on to discuss predictions in more detail. It notes, however, that many of these predictions depend on what we do now.

What is a carbon budget?

A good source of information on the global carbon budget is online from the Global Carbon Project.

The IPCC and other experts have been giving increasing emphasis to the concept of overall “carbon budgets”. Labor’s Clean Energy Future Act put this concept into Australian law for the first time, by requiring the Climate Change Authority to consider a global carbon budget in setting emissions goals.

Carbon budgets refer to how much extra CO2 and other greenhouse gases humans can put into the atmosphere before even greater levels of global warming happen. The world has already used one third of the budget (1700 Gigatonnes) for emissions between 2000 and 2050 that would give us a two-thirds chance of staying below 2oC average temperature rise.

Referring only to reductions in existing rates of emissions might give the idea that we “just” need to slow down to a safe level. But science tells us that CO2 in the atmosphere from human emissions is already way beyond safe levels, and will stay there a long time.

So for decades to come, we have a very limited carbon budget for the world to live within.

And (unlike Labor’s budget action for temporary budget deficits to save Australia from the Global Financial Crisis, which Tony Abbott is on the public record as having slept through) this is the sort of budget where going into deficit really would leave a debt that our children won’t be able to pay back.

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