Our Fragile Earth

Jenny RieszUniversity of Queensland

• Consider our fragile earth

– Such a beautiful, complex organism

• Everything on earth is interconnected and intertwined

– It sits in a delicate balance…

• Climate is the average of weather over a long time

• ‘Climate change’ therefore is a change in the average weather

• You’ve probably heard of global warming– The idea that our planet is getting a little warmer

– This doesn’t sound too bad, right?

– Global warming is just one aspect of climate change• I want to discuss all the other aspects as well

• Climate has always been variable – Glacial periods occur through Earth’s history along with periods of warmer

average temperature than today.

– This variability is natural and is caused by many things

• Why all the fuss then? – If climate changes naturally over time, why are scientists concerned?

Climate Change

• Global temperature change (between glacial and interglacial periods) occurs normally at a rate of 0.05 – 0.005°C every 100yrs.

• In the last 50yrs the global average temperature has increased by 0.5 degrees!

• This is between 20 and 200 times the normal rate, and it’s accelerating!

There is no debate that average global temperatures are increasing frighteningly fast

• What is causing this incredible global temperature increase?

The Greenhouse Effect

Figure from “The Wonders of the Weather” by Bob Crowder

Some solar radiation is scattered back out into space by the

atmosphere.

A substantial portion of the solar radiation

passes through the atmosphere and about 51% is absorbed by the

earth’s surface and warms it. Infrared radiation is

emitted from the earth’s surface

Some of the infrared radiation is trapped by the atmosphere, and

warms the earth’s surface

• The gases in the atmosphere that trap heat near the earth’s surface are called greenhouse gases

• There are many greenhouse gases – Carbon dioxide (CO2)

– Methane

– Nitrous oxide

– CFCs

– Ozone

– Some sulphur compounds

• CO2 is the most abundant of these

• Ever since complex life first evolved, atmospheric CO2 has helped keep the planet above freezing

• Because of CO2 in our atmosphere, the average temperature on the surface of our planet has been maintained at a life-friendly 14°C

• Over the past 200yrs, however, the concentrations of CO2 and these other greenhouse gases in the atmosphere has changed considerably

• It seems inconceivable that we tiny humans could do anything to affect the vast atmosphere of the earth

• This is not the case!

– If the earth was an onion, our atmosphere would be no thicker than the outermost parchment skin

There is no debate that atmospheric CO2 concentrations are increasing at an unprecedented rate.

Oil discovered

Start of the Industrial

Revolution

Today

Since industrialization, the concentration of CO2 in the atmosphere has risen from about 280ppm (parts per million) to over 370ppm

The present CO2 concentration has not been exceeded during the past 420,000yrs and likely not in the past 20 million yrs

(humans only appeared on earth 2 million yrs ago!)

The earth’s fragile atmosphere, as seen from a shuttle

• Global population growth coincides almost exactly with the increase in atmospheric CO2

There is overwhelming evidence that human activity is causing the increase in CO2 in the atmosphere!

• Models of the greenhouse effect very convincingly reproduce the observed increase in temperature

– Given the amount of CO2 in the atmosphere, and the magnitude of the effect we expect it to have

• Ice core records show that whenever atmospheric CO2 levels increase, global temperature increases.

• The greenhouse effect is by far the most likely cause of the rapid temperature increase we are observing

• Recently, proof positive of global warming was published in Science:

– A study by James Hansen and colleagues revealed that Earth is now absorbing more energy than it’s radiating to space (an extra 0.85W per square metre)

– To stay at a constant temperature, the earth must radiate exactly the same amount as it absorbs

– If the earth is absorbing more than it is radiating, it must be warming up.

Hansen, J. et al. 2005. Earth’s Energy Imbalance: Confirmation and Implications. Science 308, pp. 1341-45.

• It is agreed by the most respected scientists on the planet that

– The earth is warming up unnaturally fast

– WE are causing it with our emissions of CO2

• Global population is increasing

– 9 billion predicted by 2050

• (Currently 6.6 billion)

• Energy consumption is increasing

– Fuel demand is expected to double by 2025

• Economies in India and China are exploding

New coal-fired plants projected to be built:

1999-2009: 249 (half in China)

2009-2019: 483

2020-2030: 710 (1/3 in China)

Average lifetime of a coal-plant: 50yrs

The CO2 they emit will continue to warm the planet for centuries.

• CO2 concentrations will keep increasing

• It is estimated that the atmospheric lifetime of carbon dioxide is between 50-200 years

• This is significant because it means that there is substantial inertia in the CO2 concentration

– Even if we stopped emitting CO2 immediately, earth wouldn’t reach a new stable climate until 2050!

CO2 Inertia

What effect will this have?

• The earth is so complex that it is extremely difficult to predict the exact outcomes of CO2 emissions

– There are so many factors to consider

– They are all interconnected

• BUT

– All models predict temperatures will continue to rise…

What will be the effect of rising CO2 levels?

• It has been generally accepted that a rise of more than 2°C would constitute ‘dangerous climate change’.

• Temperature rise past this point will have a permanent and irreversible effect.

ALL models predict that global average temperature will continue to rise

Credible studies have made a point of treating uncertainties conservatively and many even exaggerate them!

What will be the effects of temperature rise?

What will be the effects of temperature rise?

THC: Thermohaline circulation

Have you been snorkeling?• Not only is the reef beautiful, it is a massively

important habitat

• Reefs provide habitats for:– 1 500 species of fish– More than 300 species of hard, reef-building

corals– More than 4 000 mollusc species– Over 400 species of sponges – Anemones, marine worms, crustaceans (prawns,

crabs etc.) and echinoderms (starfish, sea urchins etc.).

• Reefs are also:– Feeding grounds for dugong– Support fleshy algae that are a major food source

for countless species– Nesting grounds for turtles– Breeding areas for humpback whales– Breeding areas for hundreds of bird species

• Most ocean life is connected to coral reefs

• Coral reefs are one of the most fragile habitats on earth

– They are particularly susceptible to climate change

Coral bleaching at Great Keppel Island, part of the Great Barrier Reef, in 2002. The

coral will soon break down to rubble.

• Further rise in global temperature is predicted to have the following effects on the Great Barrier Reef:

– 1 °C increase - 82% bleached

– 2 °C increase - 97% bleached

– 3 °C increase - total devastation

Reported in Oct 2002 by Dr Terry Done at a meeting of 15 of the world’s greatest authorities on coral reefs

• Apart from representing a horrifying loss of biodiversity, losing the reefs represents massive financial losses– Tourism

• Tourism is Australia’s second largest income earner

– Fishing and seafood industry

• Annual value of seafood production in Australia: $2.2 billion

– Globally, reefs yield around US$30 billion per year!

• Due to the interconnected nature of the reef with other habitats it is impossible to predict the far reaching consequences of their destruction.– What other industries will suffer?

• When ice floating in water melts, the level of the water doesn’t change

– The ice is less dense than the water, which is why it floats

• The problem is ice that is sitting on land

– Glaciers

– The Greenland ice cap

– When these melt, the ocean levels will rise…

Rising temperatures means melting ice…

Satellite image of the Arctic in 2003, which illustrates the diminished range of summer ice since 1979. The Greenland ice cap can be seen to the right.

The Greenland ice cap contains enough water to raise global sea levels by 7m.

• Sea levels have already risen substantially

• Estimates of how far it will continue to rise vary widely

Effects of ocean rise

• Many major cities are port cities– Two out of every three people on earth live within 80km of the coast

– In Bangladesh alone, more than 10 million people live within 1m of sea level

• Ocean rise will have a major effect on economies– The Netherlands is already planning construction of a ‘superdyke’

– The Thames barrier is to be strengthened

– It will cost the global economy billions of dollars to deal with rising sea levels

Positive feedback

• 1/3 of the suns rays hitting earth are reflected back into space– This is due to the earth’s ‘albedo’ (reflectivity)

• Ice, particularly at the poles, is responsible for a lot of that albedo– Ice reflects back 90% of the light hitting it

• Water is a very poor reflector– It only reflects back 5-10% of the light hitting it

• Melting ice means accelerated global warming!

• It is also predicted that local climates will undergo substantial changes– Temperature

• In response to a global average increase of 2°C, Australia’s local temperature may increase by up to 5°C!

– Rainfall

Australia’s rainfall over the past 54yrs.

Darkest red areas indicate losses of more than 50mm of rain per decade, while the darkest blue have gained a similar amount.

This has a massive impact on the local flora and fauna. The change is so rapid that they simply cannot keep up and instead die out.

• Dealing with local climate change will be massively expensive– We are already facing very serious problems with our water supply

– Dealing with this will require new pipelines, desalination plants, expensive water transport costs

– A planned desalination plant near Perth will cost $350 million to build, and will provide only 15% of Perth’s water

• Reducing greenhouse gas emissions may be expensive– But how much more expensive is it to do NOTHING?

• Have you been whale-watching?

• Warming temperatures means loss of habitat for species that need to live in cold areas to survive:– Arctic and Antarctic species:

• Whales, seals• Birds, penguins

– Alpine wildlife• Bears, goats• Squirrels, birds

These species have moved on average 6km north per decade, and retreated up mountainsides 6.1m per decade

Soon no suitable habitat will remain.

Why does loss in biodiversity matter?

• We are STILL discovering new species– A great deal of our medical insight comes from nature

– We are loosing species of potentially immense benefit before we even know they exist!

– Biotechnology is a hugely important, rapidly growing field• And it’s mostly based on biomimetics! (copying nature)

• Everything is connected– Once one species becomes extinct, the delicate

ecological balance is upset

Extreme weather events

• Global warming will significantly increase the incidence of extreme weather events

• So far, global temperatures have increased 0.63°C, and we have seen:– 1997-98: Most powerful El Nino (drought season) ever recorded– 1998, Mitch: Most devastating hurricane in 200yrs

• 10,000 people killed

• 3 million people homeless

– 2002: First South Atlantic hurricane ever– 2002: Floods in China of historic magnitude

• 100 million people affected

– 2003: Hottest European summer on record– 2004: One of the worst storm seasons ever experienced in Florida

• What can we expect with the predicted 3°C rise?

• Dealing with these events in developed countries costs a phenomenal amount of money!

Global Dimming

• High levels of pollution due to industrial processes are now thought to actually have a cooling effect – The pollution reflects more solar energy back into space

• This offsets the warming due to CO2

• Strategies to ‘clean up the air’ may enhance greenhouse warming further!

• This would mean that we may have underestimated the magnitude of the global warming problem we face.

Tipping Points

• So far we have assumed that the present trends will continue

• However, earth is known to have ‘tipping points’ where conditions suddenly ‘snap’ and a new world order is created

• Two main ones predicted by computer simulations:– Demise of the Amazon rainforests

– Slowing or collapse of the Gulf Stream

The Collapse of the Amazon Rainforest

• Computer simulations predict that global warming will cause significant reduction to the amount of rainfall over the Amazon Rainforest

• This is likely to stress plants to the point that the collapse of the Amazon will become inevitable

• When the rainforest collapses, it will release a massive amount of CO2 into the atmosphere

• This positive feedback will hugely accelerate global warming– 1000ppm of atmospheric CO2 by

2100, instead of 710ppm otherwise predicted

The Gulf Stream

• The Gulf stream transports vast amounts of heat north to Western Europe

– It brings almost 1/3 as much as the sun alone

• It has been predicted that global warming of 2°C could switch off the Gulf Stream

• Switch off of the Gulf stream is predicted to result in:– 3°C decrease in Europe and North America

– 2°C increase in Australia, South America and South Africa

– Persistent drought in critical agricultural areas

• What will be the human response to such rapid change?

• ‘Humans fight whenever they outstrip the carrying capacity of their environment. Every time there is a choice between starving and raiding, humans raid’

• It is predicted that nuclear weapons will proliferate

• Global co-operation will break down through growing pressure for survival

“As famine, disease and weather related disasters strike, many countries’ needs will exceed their carrying capacity. This will create a sense of desperation”

2003 report for US national security outlining implications should the Gulf Stream collapse.

• Impacts are compounded by projected lack of co-operation between nations in the face of disaster– Mass starvation followed by mass emigration as Scandinavia, Bangladesh

and the Caribbean become incapable of supporting their populations

– With strained water and energy supplies in Australia and the US, there is an increased focus on border protection to keep out migrating hordes

– Potential for war is greatly heightened

Common perceptions:

• This will happen a long time in the future, and we will be able to deal with it then– It’s happening already! We are looking at massive changes by 2050.

• Weather presenters always get it wrong, scientists don’t really know what they’re talking about– Actually, predicting overall global change is much more certain than

predicting the weather tomorrow

• Almost all scientists agree, but a few don’t. This means it’s not true.– There is no longer debate about climate change in the scientific

community. The most eminent scientists the world over agree that climate change is happening, and it is a very serious problem.

• We’ll be able to fix it when our technology improves, and put everything back– We have nowhere near the technology or resources required to fix it

up!

– When the world changes, it is irreversible. We CANNOT put it back. Prevention is our only choice.

• Temperatures and carbon dioxide concentrations have been this high in the past, so it’s not serious– We have ALREADY shifted our climate far beyond that at any time

when complex life existed on earth. We are making our planet grossly unsuitable for human life.

“If you go to your GP and she says to you, 'Look, basically you're a real dead ringer for a heart attack and I need you to take the right sort of action and you need to cut out fat and you need to join a gym'.

You don't say, 'for heavens sake, how certain are you of this Diagnostic? I want this as a statistical probability density function. I want to know what the costs to me are going to be of taking this action, of cutting out red meat and no more fat, no more McDonalds, and I want to know how much the gym subscription's going to be, whether that's worth my while.

And most importantly of all, I want you, Mrs Doctor, to tell me what technological advances there are going to be between now and when I might have my heart attack that would in fact save me from the heart attack, or would it mean that I could just have a quick implantation and I'll be back at work in the afternoon?”

Dr Ann Henderson-Sellers, The Science Show, Radio National ABC, March 2005.

“What makes global warming so serious and so urgent is that the great Earth system, Gaia, is trapped in a vicious circle of positive feedback. Extra heat, from any source, whether from greenhouse gases, the disappearance of the Arctic ice or the Amazon forest, is amplified, and its effects are more than additive. It is almost as if we had lit a fire to keep warm, and failed to notice, as we piled on the fuel, that the fire was out of control and the furniture had ignited. When that happens, little time is left to put out the fire. Global warming, like a fire, is accelerating and almost no time is left to act”

James Lovelock, Independent, 24 May 2004.

• The bad news is we can’t risk not changing.

• To prevent dangerous climate change from occurring we must alter – our industrial practices

– how efficiently we use energy

– ultimately the way we produce energy

• The challenges are many– We have an exponentially growing world population

– New economies of India and China are emerging

– We have an ever increasing demand for energy

• The good news is that this is a great opportunity to evolve the way we look at the world.

• The challenges of climate change may well be the catalyst for a new era of cooperation with the planet.

What can I do about it?

• You shouldn’t feel helpless• There are many things you can do to help!

• By far the easiest way to reduce our greenhouse gas emissions is to consume less

Plug energy leaks• Any appliance involved in heating or cooling uses a lot of power

– Use the AC as little as possible, and at low power– Use heaters as little as possible (try an extra blanket!) – Use the clothes dryer less often

• Use energy efficient light bulbs– Standard light bulbs waste 90 per cent of their electricity on heat.

New compact fluorescent "spiral" bulbs are 75 per cent more efficient

– Up to 10% reduction in household emissions

• Unplug unused appliances– Those black boxes that power cell phones etc use energy

whenever they’re plugged in, even if they’re not charging your phone or appliance.

• Turn computer equipment completely off– If you’re buying a new monitor, flat screen LCD monitors use 70%

less energy than standard monitors

• Turn off the lights when you’re not in the room

• Use energy-efficient whitegoods– Up to 50% reduction in household emissions from electricity– www.energyrating.gov.au

• Install solar panels

Save water

• Water is our most fragile resource

• If we abuse our water sources, transporting and purifying water will cost massive amounts of greenhouse gas emissions– Install low-flow shower heads and faucets

• This is surprisingly easy!• Gives up to a 12% reduction in your household greenhouse gas emissions

– Have shorter showers

• Heating water soaks up 20 per cent of an average home’s energy needs. – Wash clothes in cooler water

– Turn down your water heater temperature

– Choose an efficient hot water tank

– Install a solar hot water system

• Up to 30% reduction in household emissions

Eat less meat!

• Meat production requires a tremendous amount of resources

Roughly one-fifth of the world's land is used for grazing That’s twice the area used for growing crops.

Much of this land once provided habitat for flora and fauna before being cleared for livestock.

Meat production requires more water than raising crops. Beef requires 85 times more water to produce than the same

amount of potatoes.

• A great deal of grain is fed to cattle

– By cycling our grain through livestock we end up with only 10% as many calories as would be available if we ate the grain directly

– For every 16kg of grain and soybeans fed to beef cattle, we get back only 1kg as meat on our plates.

• 20 vegetarians could be fed off the land that produces food for one person on a standard American diet

• The world’s cattle alone (not to mention pigs and chickens) consume a quantity of food equal to the caloric needs of 8.7 billion people

– This is more than the current global population of 6.6 billion!

• Many people are afraid that eating less meat means they won’t get adequate protein or other essential nutrients. – But there’s no need to worry.

– In fact, most western adults tend to suffer from excess protein.

– Even vegetarians frequently consume too much protein.

– As long as you eat a variety of foods including grains, fruits and vegetables, beans, nuts or seeds and a small amount of fat, you'll get all the nutrients you need.

Eating less meat is also good for you! Reducing meat consumption lowers the risks of heart disease and

stroke. Eating more vegetables, fruits, whole grains and legumes improves

your cardiovascular health and reduces the risks of obesity, diabetes and cancer.

Buy locally grown food• The food we eat travels further than ever before.

• Transporting foods creates significant greenhouse gas emissions

• Shipping food long distances requires packaging and chemical treatments to prevent rotting and over-ripening– Buying locally grown helps reduce the waste, energy and materials needed

in this process.

• Besides…– Fresh food tastes much better

• Food that’s been stored and shipped loses flavour

– Locally grown produce tends to be fresher and contain higher levels of vitamins than the imported variety.

• Food that has to be transported long distances is often preserved with waxes, gases and synthetic chemicals, such as fungicides and sprout inhibitors.

Don’t drive!

• Driving is the most polluting thing that most of us do. – Transportation accounts for more than 1/3 of an average person’s

greenhouse gas emissions

– Extracting, refining and transporting fossil fuels also contributes to global warming

• Bike, walk or take public transport

• Support alternatives to the car– Contact your local politician!

– Tell them you think:• Alternative transport such as walking or biking is healthier• Alternative transport is better for nature• Alternative transport makes city living better and more affordable

– Owning a car is expensive!

• Choose a home close to regular destinations

Drive smart

• Buy an energy efficient car – Up to 70% reduction in transport emissions– www.greenvehicleguide.gov.au

• Keep your car running smoothly– Change the oil– Maintain the mechanical systems– Check the tires

• Under-inflated tires increases fuel consumption

• Drive smart– Don’t idle

• More than 10 seconds of idling uses more fuel than restarting

– Travel light• Hauling unnecessary weight increases fuel consumption

– Accelerate smoothly• Jack-rabbit starts consume up to 50 per cent more fuel than steady accelerations.

– Minimize air conditioning

• Car pool

• Change to an accredited green power option

– You can choose to pay a little bit extra on each electricity bill to buy energy from renewable sources

• Buy green alternatives wherever possible

• 4 nations are yet to sign the Kyoto Protocol limiting CO2 emissions

– USA

– Australia

– Monaco

– Liechtenstein

• Australian emits more CO2 per capita than any nation on Earth

Get involved, stay informed

• Politicians need to know that you care about climate change– Contact them!

– Elections are a great opportunity to put particular issues on their agendas.

– Here are a few ways to be effective in your communications:

• Be concise.

• Suggest specific action to be taken.

• Focus on the public interest. Explain why you think your request will benefit the public.

Get involved, stay informed• Calculate your carbon footprint, and neutralise it!

– You can calculate your carbon footprint, including household, car and air travel emissions and then, for the cost of a cup of coffee a day, neutralise them.

– www.climatefriendly.com

– It’s very easy!

• Read and find out more…– ‘The Weather Makers – The History and Future Impact of Climate

Change’ by Tim Flannery • (2005), The Text Publishing Company, Melbourne

• Talk to your friends about climate change– Let other people know why you are concerned and why they should

be too

• The best evidence indicates that we need to reduce our CO2 emissions by 70% by 2050.– If you own a 4WD and replace it with a hybrid fuel car you can

achieve a cut of that magnitude in 1 day, rather than half a century!

– Buying green energy, at the cost of a cup of coffee per day, makes an equal cut in your emissions.

– If you vote for a politician who has a deep commitment to reducing CO2 emissions, you might change the world.

• You can, in a few months, rather than the 50yrs allowed by some governments, easily attain the 70% reduction in emissions required to stabilize the Earth’s climate.

• We now stand at a threshold and face alternative futures– One too awful to contemplate

– One where we can continue to thrive and prosper, but within the ecological limits of the natural world we inhabit

• We have just enough time to choose which of these futures we want.

• You can download these slides:

– www.jenni.riesz.com.au

• Misc

– Files to Download

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