Australia's Floods: A Climate Change Opportunity?

Climate change has played a role causing the Australian floods. Looking at both this role and how people respond could tell us volumes about our future.

Floodwaters peaked in Brisbane yesterday. They hit a high of 4.46 meters, submerging the central business district and damaging at least 20,000 homes.

Heroic and poignant scenes played out across the region. These included a tug boat singlehandedly saving the city’s iconic bridge by steering detritus clear and, my personal favorites, an image that went viral on twitter of a snake carrying frog on its back through the flood and a man who saved a kangaroo. Twitter users also created one of the more entertaining hash tags of late, #brislantis, to keep tabs on the state of the city.

Extreme rainfall spawned this deluge of water and creativity. Australia’s Bureau of Meteorology recorded the heaviest rainfall totals for a three-month period ever between October and December. As the map below shows, in some places, rainfall was over 400% above the average.

Floodwaters from those months didn’t have long enough to recede before the next round of rains hit. In the past week, some areas have received over 15 inches of rain.

The Causes

The root of this flooding is two ocean phenomena. The one you’re probably most familiar with is La Niña, a natural event where ocean temperatures that are cooler than normal off the coast of Peru. Just like a seesaw, warmer ocean temperatures generally occur across the Pacific off the coast of Australia at the same time. These conditions generally favor a longer and wetter rainy season in Australia.

This year’s La Niña is looking to be one of the strongest ever recorded, if not the strongest. However, it’s only part of the story.

Warm water in the Indian Ocean is the other big driver of rainfall in the Queensland District. As luck would have it, the Indian Ocean is also experiencing record warm waters. However, this warming is not tied to natural causes. Since 1965, the Indian Ocean has been warming in a pattern that is consistent with manmade climate change. The graph on the left gives you an idea of what that warming looks like.

Across all ocean basins, there has been a similar warming trend for decades. Warming waters lead to more evaporation, which commits more water to the atmosphere and in turn causes more extreme rainfall events.

The Response

How individuals and governments respond to the floods could provide clues for how to adapt to climate change. Australia happens to have one of the best disaster response systems in the world so other governments should pay attention. Whether the response stands in contrast to the US government’s handling of Katrina remains to be seen. However, early reports indicate drastically fewer deaths, which is a very encouraging sign.

Though the system is good, it’s not without faults. Australia is one of the few developed countries without its own weather satellite system. It has to rely on the Italian space agency for data.

In the National Times, Professor Linlin Ge of the University of New South Wales opines, “One of the great challenges in dealing with flooding over vast areas is knowing what the big picture looks like. Another is getting that information quickly enough to make it useful to people working on the front lines of disaster response.”

The time to ferry data from space to Italy to Australia slowed the warning and response processes. In one case, a flood warning arrived six hours after the flood hit.

Beyond the Response

Response is only one aspect of climate adaptation. Preparedness is equally important, if not more so.

On a longer timescale, that means using seasonal forecasts to be ready. Computer models predicted a La Niña would develop many months ago. That should’ve set off an alarm somewhere to start preparing for heavier than usual rains. Yet the connection between seasonal climate information and disaster preparedness remains pretty weak. This is in part because the two fields don’t speak the same language. Bridging that gap could go a long ways towards saving lives.

There are some encouraging efforts on the ground, though. The Australian Red Cross put out a very timely report in November 2010 on using traditional knowledge to prepare for disasters. Nobody knows regional climate better than the people who live there, especially if they’ve been there a long time. Putting this knowledge together with science has the power to make a big difference on the ground.

Small projects have already shown results. These projects are as simple as color-coded stakes near a river to show historical flood levels or comparing climate models with more traditional seasonal forecasting. They’re simple ideas but they work.

These and other solutions are going to be essential in our changing climate. Adaptation often gets kicked to the curb in hopes of getting people to focus on cutting emissions. But the reality is that even if emissions dropped to zero today, there will still be some wild weather ahead of us. Preparing for it using technology, science, and local knowledge is the best way forward. Hopefully some positive things will come out of the floods in Australia to show what exactly that path will look like. Otherwise Brislantis won’t be a very comfortable place to call home.

Photo credits: Erik K. Levand (top), Australia Bureau of Meteorology (middle and bottom)