Impacts of Climate Change in the Tropics

Mike Jones

Botany Department

School of Natural Sciences

The greenhouse effect

“Climate Change 2007”The IPCC 4th Assessment

Report• 2,500+ scientific reviewers• 800+ contributing authors

• 450+ lead authors from• 130+ countries• 6 years work

• 4 volumes• 1 Report

Atmospheric concentrations of important long-lived greenhouse gases.

Source: IPCC, 2007

Changes in Mt. Kilimanjaro ice cap and snow cover over time

Source: IPCC, 2007

Record of recent warming.

Source: IPCC, 2007

Examples of regional impacts as warming occurs

Source: IPCC, 2007

Relative vulnerability of coastal deltas

Source: IPCC, 2007

IPCC conclusions

• Africa is one of the most vulnerable continents to climate change and climate variability, a situation aggravated by the interaction of ‘multiple stresses’, occurring at various levels, and low adaptive capacity (high confidence).

• African farmers have developed several adaptation options to cope with current climate variability, but such adaptations may not be sufficient for future changes of climate (high confidence).

IPCC conclusions

• Agricultural production and food security (including access to food) in many African countries and regions are likely to be severely compromised by climate change and climate variability (high confidence).

• Climate change will aggravate the water stress currently faced by some countries, while some countries that currently do not experience water stress will become at risk of water stress (very high confidence).

IPCC conclusions

• Changes in a variety of ecosystems are already being detected, particularly in southern African ecosystems, at a faster rate than anticipated (very high confidence).

• Climate variability and change could result in low-lying lands being inundated, with resultant impacts on coastal settlements (high confidence).

• Human health, already compromised by a range of factors, could be further negatively impacted by climate change and climate variability, e.g., malaria in southern Africa and the East African highlands (high confidence).

Mitigation

• So far most discussion on tackling climate change has focussed on mitigation.

• Mitigation involves limiting emissions in order the lessen the severity of climate change.

• Even if we reduce GHG emissions now, some degree of climate change is inevitable and unstoppable.

• Carbon dioxide remains in the atmosphere for around a century.

Carbon sinks in the African jungle.

Between 1968 and 2007 African forests stored 0.63 t C ha-1 yr-1

Global tropical average is 0.49 t C ha-1 yr-1

Two explanations:Forests recovering from disturbanceOrDirect effects of rising CO2

WWW.afritron.com

Reducing Emissions from Deforestation and Forest Degredation (REDD)

• Forest removal accounts for 20% of C emissions.

• Tropical forests account for 50% of land-based sinks.

• REDD is a UN financial programme to reduce emissions in developing countries.

Wetland Sinks -Papyrus swamp vegetation

Eddy Covariance Equipment.

•Sonic Anemometer

•Open Pathway Infra Red Gas Analyser

•Net Radiometer

•Quantum Sensor

•Wind Speed and Direction

•Temperature and Relative Humidity

EC Data - Diurnal CO2 Flux in Papyrus.

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C Release Respiration C Release Respiration

C Uptake Photosynthesis

Adaptation

• Adaptation means reducing vulnerability to changes in the climate.

• It is the adjustment of a system to moderate the impacts of climate change, to take advantage of new opportunities or to cope with the consequences.

• Poverty has an impact on adaptive capacity. It means fewer resources to make adaptations.

• Compare the ability of the Netherlands and Bangladesh to adapt to sea level rise.

• Tackling poverty is essential if people are to have the capacity to adapt to climate change.