Long term Climate Change

Changing Weather Patterns

©Jacques Marais
Day-to-day weather predictions are easier to predict than longterm weather patterns
Long-term climate change ultimately plays out in changes in our daily weather. Since different parts of the planet enjoy different kinds of weather, how climate change manifests itself will be different in each region. In 2005 one side of the planet was laid waste by the hurricane that tore into the Mississippi Delta. On the other side of the planet, East African countries buckled with hunger as droughts left rural grain stores empty. These kinds of weather anomalies have happened throughout history so there's no reason to predict that these two events are harbingers of worse to come.

But, as the scientific community explains, ongoing weather anomalies around the planet (the extremes, not necessarily the norms, piece together like a jigsaw puzzle with an emerging image that supports computer-generated climate modelling. I know it's difficult to swallow long-range predictions by climatologists. After all, how can we believe them when the local meteorological office cannot guarantee the short-term forecast for Saturday's cricket? It's difficult to predict exactly whether tomorrow's maximum will be 35°C or 33.5°C.

What the weather people are usually right about is the general trend. And yes, sometimes they even get that wrong. Just because they are a little off occasionally does not mean they are peddling snake oil. Predicting tomorrow's weather is not the same as guessing the next decade's climate. Climate change modelling is extremely complex - even the most confident scientists admit that. But as computer modelling becomes more sophisticated, and the binary codes behind them ever more potent, scientists can predict with greater confidence the trends we are likely to see in the next one hundred years. What will the world of our future look like? Hell won't freeze over, but Europe certainly might.

Climate Change on the Rise

©Jacques Marais
Frozen ground in the Karoo, South Africa
The Gulf Stream is a massive body of warm, salty water that cools and sinks when it reaches the North Atlantic, before starting the long haul back to the Antarctic along the ocean floor. It's part of the larger thermohaline circulation that distributes energy around the globe and drives the planet's climate.

A slumbering crisis lies at the place where this body of water cools and sinks - Greenland. It's the second largest icecap in the world and it's melting fast. Oceanographers fear that the amount of fresh, cold water flushing off Greenland into the head of the Gulf Stream could halt this conveyor belt - it has happened in the geological past. Significantly, a decrease in salinity has been recorded since the 1960s. A recent measurement was taken of the circulation process of the Gulf Stream across the 25° N line of latitude in the Atlantic Ocean and compared with similar measurements from 1957, 1981, 1992 and 1998. The journal ‘Nature’ reported that this showed a slowing of the circulation of water by almost a third between 1957 and 2004.

Scientists now predict a 50 percent chance of the Gulf Stream being halted. While it might not happen within the next hundred years, it could change the face of continental Europe and the British Isles.

© Leonie Joubert