For a glimpse into the future

Our fascination with climate change is still going strong, but despite sceptics declaring forecast tools inaccurate, experts are confident that margins of error can be contained, Daniel Bardsley writes.
A sandstorm, which blanketed Abu Dhabi earlier this summer, left residents navigating through low visibility. Delores Johnson / The National
A sandstorm, which blanketed Abu Dhabi earlier this summer, left residents navigating through low visibility. Delores Johnson / The National

Wondering what will happen in the future is something we all do, whether it’s daydreaming about where we will be in our careers in a few years, or considering what retirement might bring.

But making firm predictions is next to impossible since who knows what hand fate will deal us? While the course of our lives may be difficult to predict, the future is easier to forecast when it comes to the weather, even a long way into the future.

Scientists have long been predicting what our climate will be like in several decades, although global forecasts for, say, temperature, vary widely.

According to the United States National Research Council, for example, the global average temperature will increase by 1C to 6C by 2100, with the outcome depending on the model used and the level of greenhouse gas emissions.

Closer to home, researchers at the Masdar Institute of Science and Technology in Abu Dhabi recently announced forecasts for the UAE’s climate.

Changes are not consistent across the UAE, but in the Abu Dhabi area, for example, researchers have identified a trend of higher temperatures, lower rainfall and reduced soil moisture. We can expect these patterns to continue in the next 30 or 50 years.

The models, involving complex mathematical analysis and published in a series of scientific papers, use two approaches. One is purely statistical: looking at past trends in temperature, precipitation, soil moisture and the like, both globally and locally.

Some of the UAE data goes back 110 years, and one approach uses this information to extrapolate into the future. The other method involves simulating how the climate works.

But just how accurate, and testable, can models of something as complex as the climate be?

The answer is of interest well beyond academia, because there are few areas of science that capture the imagination of the public more than climate change does; many without scientific training unashamedly declare themselves sceptics or believers.

Dr Taha Ouarda, a professor of water and environmental engineering at the Masdar Institute who has led the team of climate researchers, notes that all models involve a degree of uncertainty, but this can be quantified, allowing scientists to produce a confidence boundary for any prediction. The climate in future will only fall outside this confidence limit if something unlikely has happened.

“We can also quantify the skill of a given forecasting model and select the ones that lead to better forecasts,” he says.

“The quality of forecasts is validated through historic forecasting. We place ourselves at a given point in the past and we run the model to predict the future.

Since the future has now been observed, we can compare the prediction of the model with the values that have been observed.”

This allows researchers to verify how accurate their predictions are, and the model can then be used to predict the future by taking the present as the starting point.

“Models are getting more accurate as the processes being modelled are refined, the amount of data increases and the power of computers increases,” says Dr Ouarda.

Among the many other researchers interested in how the climate is going to develop in future is Dr Andrew Russell, a lecturer in climate change at Brunel University London’s Institute of Environment, Health and Societies.

He, too, cites improved computing power as being important for today’s climate modelling, saying it is useful for understanding how climate change will affect countries or parts of them. Models, he says, have to be run over and over with slight changes to account for things that are less well understood, such as the way clouds form and influence the climate.

“Naturally, we also learn more and more about the climate system the more we study it, so this new knowledge can then be used to improve the models,” he says.

While even the lay person is likely to appreciate that predicting the climate of the future is a complex business, Dr Russell says that, on a certain level, it is not as difficult as it may seem.

Climate change is, he notes, an input-output problem, so if the correct data is used, it should be possible to produce the correct result.

“We know the energy that comes in from the sun and we know how much of that energy escapes back into space,” he says.

“If you make good, educated projections of how human emissions will change, then you can predict how the energy in the climate system will change over decades or longer.”

It is perhaps no surprise, then, that he describes projections from the 1980s of how global temperatures would change as “looking quite accurate now”.

The difficult part, he says, is working out what that extra energy does: a lot of it warms the air but some of it changes rainfall patterns or melts ice or warms the oceans. “Any of these changes will have negative consequences for human societies, but the type of changes we see in different regions are difficult to predict,” adds Dr Russell.

But is being able to look into the future, and being in a position to understand how the climate will change, of benefit to us? Short of upping sticks and moving to an area with a more equitable climate if things get too hot in the Gulf region, is it just a case of grinning and bearing it? Well, probably not, as the climatic predictions can be used in a host of practical ways.

Dr Ouarda says they can help agriculturalists to determine what crops should be grown, and they could be of use to those designing infrastructure.

“Infrastructure needs to be able to withstand winds and temperatures that will be observed in the future, not those that have been observed in the past,” he says.

The models can also be used to plan public health systems, since heat spells, floods, droughts and dust storms all have an effect on those who live in the UAE.

So, although climatic challenges lie ahead, the hope is that the country will be prepared for them.

newsdesk@thenational.ae

Published: August 22, 2015 04:00 AM

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