Climate Exchange

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the next decade, or the next century) in Beijing will probably be

warmer (or colder) than average. They do this by studying large-

scale and long-term processes, such as the Earth’s orbit, long-term

solar radiation cycles, deforestation and other changes in land cover,

ocean temperatures and currents, and greenhouse gas emissions.

Their main tools are observations of today’s climate, studies of past

climates, and computer-based modeling of climate processes.

Certain regions of the global atmosphere are strongly affected

by sea-surface temperatures and other slow-changing variables.

Researchers have demonstrated that interactions among the atmos-

phere, oceans and land surface can produce fluctuations that are

potentially predictable, and that this makes it possible to predict

the climate at seasonal and interannual timescales. The most well

understood fluctuation is known at the El Niño/Southern Oscillation

(ENSO), which is linked to interactions between the atmosphere

and the ocean in the tropical Pacific Ocean. Just like the advances in

weather prediction, these advances in climate prediction have been

made possible by steady improvements in observations and models.

While climate forecasters are demonstrating an ability to predict the

average weather of the next season or the next year over a broad area,

they cannot fine-tune the weather forecast for Week 6 in a specific

locale. Nevertheless, knowing that there is a high probability that the

coming monsoon season will have low, average or high rainfall can

help farmers and energy and water suppliers, for example, to plan

their activities. Similarly, while individual hurricanes, typhoons and

other tropical disturbances cannot be predicted beyond a few days in

advance, the provision of probabilities for the future tracks, numbers

and intensity of such storms would be extremely beneficial to society.

Concern about climate change is also helping to drive research

into the climate system and climate forecasting. The evidence avail-

able to scientists – from ice cores and other residues of ancient

climates to 21st century satellite measurements and sophisticated

models run on supercomputers – has grown exponentially. Thanks

to these advances, the level of confidence scientists now

have in their understanding of the global climate system

is ‘very high’ – defined by the IPCC as being at least a

nine in ten chance of being correct.

The scientific method that has made this progress

possible is one of humanity’s most impressive cultural

achievements. By gathering and analyzing evidence,

developing hypotheses and designing experiments to

test them, scientists have unlocked many of nature’s

most closely held secrets. The spirited debate amongst

competing theories and research teams reflects the vital-

ity of this search for a better understanding of climate

variability and climate change.

Climate services

Seasonal to multiyear climate forecasts are increas-

ingly being used to generate actionable information

for decision-making on disaster risk reduction, public

health, agriculture, fisheries, tourism, transport, and

other weather and climate-sensitive sectors. A growing

number of governments are building on their experience

in weather forecasting to customize climate information

and target it to specific users. These climate services

make it possible to incorporate science-based climate

information and prediction into planning, policy and

practice to achieve real benefits for society

Climate services often involve integrating climate

information with information from other sectors. This

requires close collaboration between agencies and

experts from different fields. The resulting information

must then be presented to users in formats that they can

understand. When presenting information in the form

of probabilities, climate service providers must take

Pre-drilling of ablative measuring rods: Uzbekistan Hydro-meteorological Service

Image: George Tarbay, NIU

Students in meteorology at Northern Illinois University, monitor air

temperatures and humidity at a weather station in a DeKalb cornfield.

The students worked on research showing trends in northeast

Illinois dew-point values

Image: Uzbekistan NMS

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