Impacts of Climate Change

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Climate Change Increases Uncertainty

Climate change and the ENSO cycles increase the uncertainty about weather patterns globally.

El Niño Southern Oscillation

El Niño Southern Oscillation (ENSO) cycles produce uncertainty for weather patterns as conditions change in different years.
El Niño sees winds decline and reverse direction, warm water moves towards South America, low air pressure increases rainfall and flood risk rises.
In contrast, ocean temperatures drop in Australasia meaning higher air pressure, less rainfall and increased drought risk.
La Niña events exaggerate normal weather and increase drought risk in South America and flood risk in Australasia.

Increased uncertainty

Climate change increases the uncertainty with weather patterns across the world, resulting in higher or lower precipitation that leads to either drought and floods.
Sea level rise and warmer sea surface temperatures increase the chance of tropical storms and the floods associated with them.

Drought risk projections

Areas that are at risk for future drought are the USA, Central America and the Mediterranean. These regions, all around similar latitude, could see a reduction in rainwater.
The Southern Mediterranean countries (i.e. Spain and Greece) are particularly at risk from drought because of their relatively high populations and reliance on the tourism industry.
Countries seeing a reduction in drought risk include northern Alaska, Asian countries and countries surrounding the Indian Ocean.

Flood risk projections

South East Asia (i.e. India and Bangladesh) is seeing an increase in the likelihood of flooding.
70% of Bangladesh is on a floodplain and the majority of the nation is only 1 m above sea level.
Climate change is likely to cause Himalayan glacial meltwater to increase and flood the rivers. Sea level rise and the increased likelihood of tropical storms (referred to as Cyclones here) means Bangladesh is increasingly at risk from flooding.

Climate Change Impacts in The Sahel

The Sahel is an arid region bordering to the south of the Sahara Desert. We can look at it as an example to see how climate change has affected the hydrological cycle in that location.

Precipitation

In the Sahel, rainfall is low, around 100mm-600mm per year.
The Sahel has a rainy season from July to September, during which 90% of the region's precipitation falls.
During the 1970s and 1980s, rain declined by around 40%. This led to drought, poverty and a civil war broke out in Eritrea and Ethiopia (as people fought for water and land).

Changes in climate

Since 1996, the climate seems to have been changing. There have been five significantly wetter years.
This increase in wetter years has been referred to as a ‘re-greening’ opportunity. Locals have taken advantage of the wetter years by ensuring the regeneration of water, retaining vegetation and low-cost afforestation.