CLIMATE change is confusing. It's either the end of the world and we're all going to die. Or it's an overblown threat involving "warmists" and the "IPCC".

If you feel like you don't fully understand what's going on, you're not alone.

Plenty of people have an opinion on what is happening. But what are the facts and how does it affect you?

1. WHAT IS CLIMATE CHANGE?

Climate change is global warming. The two are the same thing. It is the world getting hotter.

No one doubts it is happening. The last decade, 2000 to 2010, was the hottest on record. The big controversy is about what is causing it.

Warming up the planet is like knocking over the first domino. It has massive knock-on consequences which can affect all of us.

The big one is food security. A rapidly warming climate will make some places wetter and others drier. This could affect the quality and quantity of available food on the table of every single person on the planet.

And a hot planet is not good for the world's great glaciers, such as the ones that cover Antarctica and Greenland. More water flows into the ocean as those glaciers melt. Sea levels creep up. They are already unusually high.

Then you get trouble. Flooding, for instance. You can see how this just gets worse and worse.

2. RIGHT. BUT DID HUMANS CAUSE IT?

Yes. But it's understandable if you're not convinced. Plenty of people don't believe it. And sceptics have plenty of questions: What if the solar flares make the world hot? Doesn't the climate always change? Isn't it a good thing?

All of these have serious answers from very smart people. You can find these busted myths at the bottom of this piece.

But you do need to know one small statistic: 95 per cent.

That's how certain the United Nations climate science panel is that climate change is manmade.

Scientists are notorious for never being completely sure about anything. Even gravity, what keeps us stuck to the ground, is just a "theory".

But they have little doubt the huge changes they have witnessed in the environment were caused by humans.

3. REMIND ME HOW IT WORKS

Science boffins named John Tyndall and Svante Arrhenius figured out how it works in the late 19th century. It's simple. Basically:

Heat + Manmade gases that keep heat = Hot Earth

Global warming is caused by so-called "greenhouse gases". The gases, such as carbon dioxide, absorb heat and keep the planet warm enough for us to live on.

But humans - and yes, cows farting - have added so many tonnes of it into the atmosphere over the past hundred years that it has warmed up the planet.

4. SO IT WILL BE REALLY HOT?

Our summers are already getting longer by a day or two each decade, heatwave expert Sarah Perkins told news.com.au. Heatwaves are becoming increasingly common in the cooler months.

Then there's the kicker. By 2070, Australia is expected to warm between 1.0 to 5 degrees Celsius, according to the CSIRO.

It's the difference between a cool day and a scorcher where you melt into a little puddle. Just like this ice cream.

5. SO HOT IT CAUSES BUSHFIRES?

Peoples' ruined homes were still smouldering from the NSW bushfire crisis when Greens MP Adam Bandt launched a blistering attack on the Prime Minister's climate change agenda.

"This is what global warming in Australia looks like and it's going to mean more fires happening more often and some of them more severe when they happen," he told the ABC.

Some thought it was insensitive. Others wondered - if we can't talk about climate change now, when can we talk about it? So DOES climate change actually cause bushfires?

It's difficult to say. Arsonists cause fires. So do lit cigarettes, dry conditions and the high fuel load of bushland.

But heatwaves and predicted drier conditions in southern Australia can help create the conditions where bushfires are more likely to happen, heatwave expert Sarah Perkins told news.com.au.

And when they do happen, the blazes will be worse.

"It can influence increased bushfire risk," Ms Perkins, from the ARC Centre for Excellence in Climate Systems Science at UNSW said.

"These sorts of bushfires are not solely due to climate change, but they're certainly at increased risk."

6. WHAT ABOUT SEA LEVELS?

Floods are not going to smash through Australia all the way to Uluru in some kind of Day After Tomorrow apocalypse.

But yes - you should expect more floods, especially along the country's coastline.

On average the nation will experience a 300-fold increase in "flooding events" by the year 2100, according to a report released by Australia's Antarctic Climate and Ecosystems Cooperative Research Centre. That means one-in-a-hundred year floods will become considerably more common.

That figure is what would happen if the country experiences an average sea level rise of half a metre.

The CSIRO said we will feel it the most during big storms when we will see the most land inundated.

7. AT LEAST YOU DON'T LIVE HERE

We are actually lucky compared to the poor folk of the small nation of Tuvalu, found halfway between Australia and Hawaii.

It's easily one of the countries that will suffer the most. Much of the country could be flooded.

"This is a 'life or death' survival issue for Tuvalu," the country's now leader, Enele Sopoaga, pleaded with the world in 2010.

The entire population of the tiny chain of nine Pacific Islands lives under 2m above sea level. As you can see.

The global average sea level could rise by a metre by the end of the century if emissions remain high. If they are lower, levels could rise between 28cm and 60cm.

They have it tough enough already when a cyclone hits. "There are no mountains to climb, no inland to run to. Of course, there are coconut trees," Mr Sopoaga said.

Another low-lying nation, the Maldives, has reportedly weighed up moving its population to Australia.

8. THE GOOD NEWS ... AND THE ACID NEWS

Finally. Some good news from this global warming mess. More time at the beach for you!

You're in luck if you live on the east coast of Australia and find the ocean too cold most of the time. The water's getting warmer much quicker than the rest of the ocean.

Over the past hundred years the water has warmed three times faster than the global average, by 1.5 degrees instead of the 0.5 degrees average.

Sucks if you live in the ocean though. The warmer currents will disrupt how tropical fish move around, oceanographer Erik Van Sebille from UNSW's Climate Systems Science Centre said.

Meanwhile, the oceans are becoming more acidic as well. The oceans absorb around 30 per cent of the carbon dioxide humans have emitted into the atmosphere.

That's not good for any sea creatures that need a shell, such as corals, molluscs or sea snails, Mr Van Sebille said, as the ocean dissolves it. "You have deformed animals who can't build their nice beautiful shells," he said.

And that could have a huge impact on our tourist attractions - the Great Barrier Reef a case in point - our fishermen, and the wider environment.

9. WHERE DOES IT END?

A "tipping point" means we can't go back. The Earth's climate would have changed in a way that's irreversible. At least for thousands of years.

Scientists want to keep the temperature rise to 2 degrees Celsius or less, otherwise the IPCC warns we will see "catastrophic" damage.

To prevent that, the international community including the world's biggest polluters, the US and China, needs to sign a deal to slash emissions.

10. CAN I DO SOMETHING?

At the end of the day, you're just a small fish in a big blue pond hurtling through space.

There are little things you can do, especially recycling and switching off that power-guzzling air conditioner. Ultimately, the most powerful tool you have is your right to vote.

Continue the conversation on Twitter: @drpiotrowski | @newscomauHQ

DEBUNKED? ANSWERS FOR THE SCEPTICS

MYTH #1: Climate's always changing

FACT: Absolutely true. But that proves scientists' point. The climate is sensitive to forces on Earth, such as heat from CO2 emissions. So global temperatures are going up.

MYTH #2: It's all the sun's fault

FACT: The sun's heat and the climate have been going in opposite directions over the past 35 years

MYTH #3: Climate change is great

FACT: Negative impacts of global warming on agriculture, health & environment far outweigh any positives.

(Source: skepticalscience.com)

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