Caring viewers, welcome to Planet Earth: Our Loving Home. On today's program we examine the intense flooding events that recently enveloped a large part of eastern Australia
and how these floods were exacerbated by global warming. To better understand these natural catastrophes, we speak with two Australian climate experts.
The first is David Karoly, Professor of Meteorology at the University of Melbourne, Australia who was a Lead Author for the United Nations Intergovernmental Panel on Climate Change's 2007 Fourth Assessment report as well as a review editor.
He shares with other members of the Panel the 2007 Nobel Peace Prize for disseminating information to the world about climate change.
The second is Professor Matthew England, physical oceanographer, leading climate scientist and co-director of the Climate Change Research Centre at the University of New South Wales, Australia.
In December 2010 and early 2011 the eastern states of Australia - Queensland, New South Wales, Victoria and northern Tasmania - experienced flooding brought on by the La Niña effect but
with increased severity due to warmer ocean temperatures. Professor Karoly explains further.
Karoly (m): The La Niña is a pattern of changes in ocean temperatures and atmospheric winds that affects the whole of the Pacific Ocean and Southeast Asia. In fact, it really affects the whole world.
It starts with cold ocean temperatures in the equatorial Pacific Ocean and warmer than normal temperatures over the region around Southeast Asia and north of Australia.
It's the opposite of the El Niño phenomenon but the La Niña, the sister-phase if you like is associated with cold ocean temperatures in the eastern Pacific, warm ocean temperatures in the western Pacific and in the Australian region, and stronger than normal trade winds bringing moist air into the region over northern and eastern Australia.
And that warm moist air converges over Australia and leads to much heavier than normal rainfall. The last six months have been a very strong La Niña phase, much stronger than average and that's caused very heavy rainfall and flooding over much of northern and eastern Australia, particularly in December (2010) and January (2011).
So La Niña not only brings heavy rainfall to northern and eastern Australia it in effect sucks the rainfall away, or draws the rainfall away from Southern and Western Australia and what we see in Southern and Western Australia is very dry conditions in a normal La Niña phase.
What we've seen this year with the very strong La Niña is very low rainfall over southwest of Western Australian. We've had record low rainfall for the whole of 2010 over Perth, southwest of Western Australia, and record low inflow into their reservoirs.
These situations of course, the heavy rainfall in the northeast of Australia and the low rainfall in the southwest of Australia have been accentuated or made worse because we also have record high ocean temperatures around the whole of Australia.
That's not linked to La Niña, that's linked to global warming or climate change caused by increasing greenhouse gases in the atmosphere. And what we've seen is a steady increase over the last 110 years of ocean temperatures around Australia and the last few months, particularly December and the springtime in Australia has seen record high ocean temperatures - higher than we've seen for any time over the last more than a hundred years.
Supreme Master TV(f): How is climate change impacting these flooding events?
Prof Karoly (m): Sure, that's a really good question because it's very difficult to disentangle the combined effects of the La Niña, which is really the main factor bringing the warm moist air over Queensland and eastern Australia, and the effects of climate change.
They are both contributing. What we do know is that we are seeing record high rainfall over Queensland for the last three months and the last six months, and in December (2010), and in January (2011).
Not only in Queensland but also in Victoria and New South Wales. All up and down the eastern part of Australia and that record high rainfall is in fact getting some contribution, from the higher ocean temperatures.
Warm ocean temperatures mean more evaporation of moisture into the atmosphere and we've also seen record high humidities. That warm moist air when it rains leads to very heavy rainfall and that's exactly what we've seen.
Of course climate scientists have been saying that increases in greenhouse gases and climate change due to those increases in greenhouse gases will not only increase global average temperatures but lead to more moisture in the atmosphere, lead to increases in heavy rainfall and increases in flooding. And that's exactly what we've seen in the last six months over northern and eastern Australia.
Supreme Master TV (f): This is fairly close to home. We've seen a lot of these things in the news in other countries and we might of thought, “It's not going to affect us to that extent. But we've seen loss of life. In other countries crops have been destroyed. Is it getting more serious now?
Matthew England (m): Climate change is already having a significant cost on society. People will remember the bush fires in Victoria only a couple of years ago. A very senior weather expert in Australia said that is a climate change event, categorically. And that was an event that caused untold damage. Again, lives were lost, whole towns were burnt down.
And if that is an event that a senior meteorologist rates as being clearly linked to climate change, then I'd argue that society needs to have a good look at addressing this problem because these are very costly events, and we can't keep pretending the world's climate isn't changing, and just accept the multi-billion dollar cost of dealing with these very strong extreme events.
The really tricky thing for people to get their head around is the fact that we've always had bush fires in Australia, we've always had floods. These events are familiar to us but the fact that they're occurring with greater intensity, and they're coming around more often, those sorts of things are what the scientists are saying we should be aware of in terms of addressing this problem.
And what makes communicating the science very difficult is that people will say things like, "Well, Brisbane had a bad flood in 1974. Climate change wasn't being spoken about back then." And what we need to keep doing is, is informing the public about what climate change means.
And the fact that it's the progression of these events. It's the increased number of extreme events. The increased severity of bush fires in the sub-tropics; very heavy rain events in the tropics. And we're seeing this not just in Australia, we're seeing this occur globally.
All of this is consistent with our picture of how the planet will respond to increased greenhouse gases. With the planet getting warmer; it will energize the system and create a situation where extreme events are much more extreme than they otherwise would be.
HOST: The recent intense and devastating floods took Australians by surprise, inflicting immense human suffering, forced evacuations, and billions of dollars in damage to properties, livelihoods and crops. In Queensland alone, at least 70 towns and cities and over 200,000 people were affected with 35 fatalities.
As professors Karoly and England have pointed out, climate change has worsened the intensity of flooding events, but what further aggravates the severity of these happenings is the way humanity has gravely damaged the surface of the Earth.
Over 60% of Australia's landmass is used for livestock and pastures. A report by the Australian government titled “Assessment of Australia's Terrestrial Biodiversity” states that livestock grazing is responsible for:
[The] direct removal of some species; changes in the relative proportions and mixtures of species in ecosystems such as grasslands, shrublands and woodlands; alteration to habitat in mid and lower storeys of forests and grasslands; altered fire regimes; and impacts on soil structure and water infiltration.”
Source: (Assessment of Australia's Terrestrial Biodiversity 2008, (2009), p. 186)
HOST: In Queensland vast amounts of native trees and vegetation have been removed because of animal agriculture-related activities. In fact, over the last 20 years, 91% of all land cleared in Queensland was for livestock raising. Thus, tree clearing and overgrazing lead to soil degradation and loss as well as water infiltration issues, creating a further worsened scenario in the wake of any extreme downpours.
Matthew England (m): Climate change is one problem, but also the way we've changed the natural environment is another problem. And combining the two creates more problems than just having only climate change to deal with, or just the way we've changed the natural environment. The natural vegetation is a very important part of the ecosystem. It's certainly a very important way that the Earth can absorb greenhouse gases. So clearing land does affect, for example, some of the mudslides you see in some nations.
If you've cleared land there, having no vegetation to keep the soil in place is a real problem. You can have massive landslides that result from the combination of very heavy rains and a changing of the natural landscape.
HOST: Without a doubt, floods have a very deleterious effect on wildlife. Wildlife expert and spokesperson for the Australian Veterinary Association, Dr. Robert Johnson, has this to say about wildlife and the recent floods in Australia:
Quote by Dr Robert Johnson: “Some species such as birds may be able to escape more easily than others but will be affected once they try to return to their preferred habitat. We expect that semi-aquatic animals such as freshwater turtles and frogs will suffer greatly due to loss of habitat.
For freshwater and marine turtles it is the breeding season, so numbers will be profoundly reduced as nests are destroyed.
The unseen victims of the floods will be small land-based animals that make homes in bushes, and unfortunately many of these species are already under threat from other factors such as habitat destruction….. We also expect that large numbers of wombats and echidna will have drowned in burrows.”
HOST: Climate scientists are predicting more and more harsh weather occurrences worldwide and possible runaway climate change if we do not quickly act to reduce our greenhouse gas emissions.
Studies have shown that the cycle of producing and consuming animal products is the source of the majority of these human-generated deadly gases. [ In fact, the 2010 United Nations Environment Programme (UNEP) study “Assessing Environmental Impacts of Consumption and Production: Priority Products and Materials,” found that animal-based food is the common denominator with respect to most of our planet's serious environmental issues.
In short, the vegan solution to climate change is in our hands and begins when we choose to only put plant-based food on our plates. Our sincere gratitude, professors David Karoly and Matthew England for your insightful explanations about flooding events and how they are significantly worsened by climate change.
We pray that the whole of humanity quickly awakens to their noble, true, compassionate nature so that the healing and restoration of our beautiful planet may soon begin.
For more information on today's guests, please visit the following websites:
Professor David Karoly www.research.science.unimelb.edu.au/profile/eminent/karoly
Professor Matthew England web.maths.unsw.edu.au/~matthew
Thank you for joining us today on Planet Earth: Our Loving Home.