The world’s largest, most powerful and record breaking cyclone slammed into Southern Africa last week; it brought unprecedented rainfall that wrought destruction and loss of life. Freddy was borne on West of Indonesia in early February and insidiously moved 7,000 km across the Indian Ocean to crash into Madagascar and thence onto Mozambique and finally Malawi.
DOUGLAS RABASH
At one point wind speeds of 215 kph were recorded. Many have rightly attributed the severity of the storm to Climate change, because as the atmosphere warms so water vapour increases. According to the laws of thermodynamics, for each degree Celsius increase in air temperature there will be a 7% increase in water vapour. Consequently, with the increase in atmospheric water vapour, precipitation intensifies. It is no coincidence that the prevalence of the highest intensity storms has occurred as annual temperatures have risen. The latest IPCC report issued this week confirms that atmospheric temperatures have increased 1.3C from pre-industrial level and CO2 levels are now 423 ppm. The report grimly forecasts CO2 of 450 ppm by 2050 and temperature increases of 3C. At plus 3C the water vapour will be 21% more – by applying the law of thermodynamics. Cyclone Freddy and his ilk will be common place and no longer extreme. Social disruption will be total. We need to worry.
The blame or culpability for climate change damage is not straight forward. Yes, it is true that the polluters of the industrial north are most certainly to blame for emitting greenhouse gases that have caused global warming. But what of the producers of fossil fuels such as Saudi Arabia that have grown very rich on the sale of fossil fuel – and other producers. And what of global consumers whose insatiable appetite for all kinds of goods and services that have driven the demand for energy. We all have benefit from the modern industrialised world. Many developing countries have thrived by selling fossil fuels, others by using the fuels and most of us have indulged as consumers – just pause for a moment to consider the rise of the mall. When we drive our nice new or second-hand cars we need to remember that Ford emitted about 6 tons of CO2 to produce it and the owner about 4 tons per year to operate it. The arguments around culpability will continue to circle.
The other contributor to the devastation wrought by Freddy and his family of global climate terrorists is land management. For example Malawi has lost almost all its forest cover, incredibly only 3% of it remains. Run-off from vegetation depleted land is rapid, almost no rainwater is absorbed into the ground. Whereas forests are like sponges, it may take many hours or even days for water to percolate through into rivers and flooding. Wetlands are also a sink for surface water but these have been drained for farmland. It is sadly ironic that the SADC regional coordination for forestry used to be headquartered in Malawi – the fifth most deforested country on Earth – until all sectors were concentrated in the SADC HQ Botswana.
Flooding in Pakistan in 2022 was more devasting than Malawi – it killed 1,700 people and caused $15 billion in damage while 300 died in Malawi causing significant loss of housing and farm produce – the amount of which has yet to be assessed. Of course the Pakistan population is ten times that of Malawi, so on a per capita basis the impact of Freddy was more severe. According to a Reuters Journalist, floods, other water-related disasters could cost global economy $5.6 trillion by 2050. https://www.reuters.com/business/environment/floods-other-water-related-disasters-could-cost-economy-56-trillion-by-2050-2022-08-29/. This includes the impact of rising sea levels on coastal populations. Generally the costliest severe weather event types are drought, with an average cost of $10.9 billion per event; wildfires, with an average cost of $6.3 billion per event and flooding, with an average cost of $4.8 billion per event. The source for this is https://www.ncei.noaa.gov/access/monitoring/dyk/billions-calculations.
The impacts of all such extreme weather events can be contained and minimised given sufficient resources. Climate change loss and damage funding should be directed to measures that will reduce impacts. While drought – affecting countries like ours – is the most intractable challenge, arguably flooding is most preventative extreme weather event which calls for a total rethink on land management. Reforestation on a massive scale is justifiable because not only do forests stabilise landscapes and reduce the rate of water runoff – trees take in carbon dioxide. But staying with adaptation rather than mitigation – in climate change parlance – the benefits of tree planting are irrefutable. The runoff coefficient from one hectare of dense natural forests is about 0.1 while that for degraded farmland would be about 0.7. Note that a runoff coefficient of 1.0 is that of surface water on built up areas like concrete and paved roads. Forests help maintain high water quality, influence the volume of available water, and regulate surface and groundwater flows. Forests also help reduce water-related risks such as landslides, floods and droughts and prevent desertification and salinization. The priority for Malawi should be a national reforestation programme that especially targets watersheds.
Flood hazard mapping is a very useful tool for governments to have. Malawi flood hazard mapping shown reveals that most of the flooding is likely to occur in the South and where seasonal rivers flow into Lake Malawi. Such flood hazard mapping appears not to have been produced for Botswana, but it will be useful to prepare adaptation plans for our critical infrastructure. But in a water scarce country, would it be unfair to say that flooding is not really considered to be of concern, even though Dineo and other cyclones should have taught us a lesson? chttps://www.researchgate.net/publication/368494562_Geohazard_assessment_of_Malawi/figures?lo=1&utm_source=google&utm_medium=organic.
Pressure of land for producing food to enhance food security needs balancing with the need to avert flooding that will destroy crops that exacerbates food security. Tree planting needs to be stepped up. There remains a challenge to reverse the loss of permanent vegetation and the biodiversity that it generates. The SADC Green Belt Programme needs accelerating. Trees need not only be fruiting, but indigenous species that stabilise land, counter desertification and sequester CO2. Yesterday 21st March was World Forest Day so let us celebrate this by ensuring tree planting must be mainstreamed into land management and start reducing the impact of cyclones like Freddy and Dineo – by law if necessary. Legislators to take note.
PULL QUOTE 1
It is no coincidence that the prevalence of the highest intensity storms has occurred as annual temperatures have risen.
PULL QUOTE 2
According to a Reuters Journalist, floods, other water-related disasters could cost global economy $5.6 trillion by 2050.
PULL QUOTE 3