Bogus linking of Cyclone Idai Mozambique to climate change

The news last week was full of reports of the impacts of Cyclone Idai on South-East Africa, particularly on Mozambique. This has inevitably been linked to climate change. Jaime Jessop brings attention to a “Climate Justice” article at the Conversation “Cyclone Idai: rich countries are to blame for disasters like this – here’s how they can make amends“. The article states

It is inevitable that people will connect Idai and climate change. It is always tricky to establish a direct causal link, but thanks to the evidence provided by a number of reports from the Intergovernmental Panel on Climate Change (IPCC), including this most recent one from October 2018, we know that climate change is bound to increase the intensity and frequency of storms like Idai. At the very least, this crisis is a harbinger of what is coming.

As Jessop points out, the most recent IPCC SR15 has low confidence in any increase in trends in global cyclone activity, nor in the severity. In term low confidence I interpret to mean that evidence, if available, is highly speculative and/or is contradicted by better evidence. The Conversation article fails to read the evidence. Climate change is not “bound to increase the intensity and frequency of storms like Idai“. Even if that were, Idai is not caused by climate change.

At the BBC Matt McGarth tries to make the climate connection,

While Cyclone Idai is the seventh such major storm of the Indian Ocean season – more than double the average for this time of year – the long-term trend does not support the idea that these type of events are now more frequent.
The interesting thing for the area is that the frequency of tropical cyclones has decreased ever so slightly over the last 70 years,” said Dr Jennifer Fitchett from the University of the Witwatersrand in South Africa who has studied the question.
Instead, we are getting a much higher frequency of high-intensity storms.
Climate change is also changing a number of factors in the background that are contributing to making the impact of these storms worse.

There is absolutely no doubt that when there is a tropical cyclone like this, then because of climate change the rainfall intensities are higher,” said Dr Friederike Otto, from the University of Oxford, who has carried a number of studies looking at the influence of warming on specific events.
And also because of sea-level rise, the resulting flooding is more intense than it would be without human-induced climate change.

Evidence of more high frequency storms

Dr Jennifer Fitchett enlarges on the change in cyclone activity at the Conversation. In Tropical cyclone Idai: The storm that knew no boundaries she states

Historically, nine storms that had reached tropical cyclone intensity made landfall on Mozambique. A larger number of weaker tropical systems, including tropical storms and depressions affect the region, with a total landfall of all tropical systems of 1.1 per annum.

The link is to an open access article.

Fitchett and Grab 2014 : A 66‐year tropical cyclone record for south‐east Africa: temporal trends in a global context – International Journal of Climatology

Table 1 contains details of historical records for Madagascar and Mozambique. I have summarized the numbers of deaths by year.

The claim of  an increase in severe storms over the last 70 years by Dr Fitchett is evidenced by a glance at this graph. But there are issues. For Mozambique there are no recorded major cyclones between 1956 and 1994, nor for Madagascar between 1959 and 1994. Does this mean that there was major cyclone drought for over thirty-five years?
The history of the two countries suggests reasons for the lack of records other than lack of events to be observed. Historically Mozambique was a lightly-administered Portuguese Colony. There was a War of Independence covering 1964-1974 and following Independence a Civil War 1977-1992. Madagascar became Independent of France in 1960. There was increasing strife, culminating in a socialist-Marxist dictatorship from 1975 to 1993. The dictatorship was largely cut-off from the outside world. 1994 was the first year both countries were clear of the major strife that afflicted them for  decades, so it is hardly surprising this was the first year in decades when the severe impacts of cyclones was reported.
A BBC Report gives colloquial evidence to support the storms being nothing unusual. A video report of Cyclone Idai says it is the strongest winds Mozambique has had in the last ten years.

The evidence of less cyclones, but a claim more high-intensity ones looks like a rejection of objective evidence in favour of sensationalist reporting.

Evidence of Sea Level Rise

The desperation is indicated by mentioning sea level rise, which has risen by a few centimetres in the 50 years. Although centered on the coastal town of Beira, Mozambique, the vast areas impacted also include parts of the land-locked countries of Zimbabwe and Malawi. The nearest point to the sea of either country’s borders appear to be much greater than 150 kilometres. For some perspective, in Britain, the furthest point from the sea is Coton in the Elms at 70 miles or 113km distance.
Singling out one person is maybe unfair. Climate alarmism is a consensus enterprise, which gives primacy to mantras, rather than verification of conjectures with evidence of the natural world. However, the false attribution of sea level rise in the article is by Dr Friederike Otto. One profile I found states:-

Friederike (Fredi) is the Acting Director of the Environmental Change institute and an Associate Professor in the Global Climate Science Programme where she leads several projects understanding the impacts of man-made climate change on natural and social systems with a particular focus on Africa and India.
Her main research interest is on extreme weather events (droughts, heat waves, extreme precipitation), improving and developing methodologies to answer the question ‘whether and to what extent external climate drivers alter the likelihood of extreme weather’. She furthermore investigates the policy implication of this emerging scientific field.
Fredi is co-investigator on the international project World Weather Attribution which aims to provide an assessment of the human-influence on extreme weather in the immediate aftermath of the event occurring.

Dr Otto also featured in Nature last year, for attributing the 2018 Northern European heatwave to climate change. As Jaime Jessop found out, the selective evidence and modelling assumptions to support this attribution was contradicted by looking at the wider data.

Policy Implications

If the real desire is to look at making rational policy decisions to ameliorate the impact of emerging extreme weather events, then it is necessary properly assess the type, severity and geographical extent and likelihood of these impacts. Otherwise resources will be wasted on projects that do not address the issues. That includes only accepting claims made about an emerging impact when they are properly verified by the evidence. Otherwise, climate alarmism will ensure that resources are directed away from making a real difference to the lives of the poorest people.

Not only is the “Climate Justice” movement singling out a few countries to pay compensation for damages without evidence of damage caused, they are also helping to ensure that resources are directed away from making a real difference to the lives of the poorest people.

Kevin Marshall

Leave a comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: