SRM: Landcare: CLIMATE CHANGE - Conclusions by leading researchers
Table of Contents:
- Facts, threats and solutions
- What is climate change?
- Conclusions by leading researchers
- Short term scenarios and the expected impacts of climate change
- What you can do to mitigate the impact of climate change
- Additional resources
CONCLUSIONS BY LEADING RESEARCHERS:
By: Prof. Bruce Hewitson, UCT: Climate trends and projections:
The physics of climate change are indisputable, evident in atmospheric carbon dioxide, global temperature increases, Arctic changes and changes in rainfall trends. Model based studies attribute this to anthropogenic actions.
The change manifests as:- increase in mean temperature
- increase in variance of temperature
- increase in mean and variance, resulting in less change for cold weather
2005 was the warmest year on record, the last eight years were the warmest in the last 100, and the last century was the warmest in the last 1200 years. Western Cape trends are not simply about becoming drier or wetter; it's a complex situation. For example, areas that are predominantly dependent on cold fronts are getting drier. But with increased humidity, fynbos captures more water in the mountains. Trends indicate increases in rainfall intense events, reduced total rainfall in the west and increased orographic rainfall towards the east. Not just change in averages, but also change in extremes.
Changes occur in space and time and place stress on all facets of the infrastructure and capacity of society.
Considerable scientific agreement about the pattern of change but uncertainty about the magnitude. Key recommendation: Adaptation, based on science. Adaptation has a very important role over the next 50 years; mitigation has a longer time span. Adaptation is complex, given the coupled natural, social system: what happens elsewhere affects us in the Western Cape (e.g. melting Arctic ice caps will affect shipping to South Africa, and therefore the economy). Climate change will not disappear with Kyoto.
By: Dr Guy Midgley, SANBI: Ecosystems and biodiversity impacts of Climate
Change
Much of the modern biota evolved under cooler conditions than currently prevail.
Succulent Karoo is more sensitive to climate change than fynbos biome
Mountains buffer the impacts of climate change
Nature provides valuable warning signs – e.g. Kokerboom
Empirical warning signs, evidenced by succulents showing distress and mortality in warming chambers
As hotter and drier conditions become more prevalent, fires burn over more often, over more extensive areas, with the concomitant possibility of the fire cycles over larger areas becoming synchronised, which means more populations would be present only as seedlings. This could result in post-fire drought and mass extinction event.
