bushfires – Cabot Institute for the Environment blog

Urgent action is needed to protect Madagascar’s forests.
Rijasolo/AFP via Getty Images

Global climate change doesn’t only cause the melting of polar ice caps, rising sea levels and extreme weather events. It also has a direct effect on many tropical habitats and the animals and plants that inhabit them. As fossil fuel emissions continue to drive climate change, large areas of land are forecast to become much hotter and drier by the end of this century.

Many ecosystems, including tropical forests, wetlands, swamps and mangroves, will be unable to cope with these extreme climatic conditions. It is highly likely that the extent and condition of these ecosystems will decline. They will become more like deserts and savanna.

The island nation of Madagascar is of particular concern when it comes to climate change. Of Madagascar’s animal species, 85% cannot be found elsewhere on Earth. Of its plant species, 82% are unique to the island. Although a global biodiversity hotspot, Madagascar has experienced the highest rates of deforestation anywhere in the world. Over 80% of its original forest cover has already been cleared by humans.

This has resulted in large population declines in many species. For example, many species of lemurs (Madagascar’s flagship group of animals) have undergone rapid population decline, and over 95% of lemur species are now classified as threatened on the International Union for Conservation of Nature (IUCN) Red List.

Drier conditions brought about by climate change have already resulted in widespread bush fires throughout Madagascar. Drought and famine are increasingly severe for the people living in the far south and south-western regions of the island.

Madagascar’s future will likely depend profoundly on how swiftly and comprehensively humans deal with the current climate crisis.

What we found

Our study investigated how future climate change is likely to affect four of Madagascar’s key forest habitat types. These four forest types are the dry deciduous forests of the west, humid evergreen forests of the east, spiny bush forests of the arid south, and transitional forests of the north-west corner of the island.

Using computer-based modelling, we simulated how each forest type would respond to climate change from the current period up to the year 2080. The model used the known distribution of each forest type, and current and future climatic data.

We did this under two different conditions: a mitigation scenario, assuming human reliance on greenhouse gas reduces according to climate commitments already made; and an unmitigated scenario, assuming greenhouse gas emissions continue to increase at their current rate.

Our results suggest that unmitigated climate change will result in declines of Madagascar’s forests. The area of land covered by humid forest, the most extensive of the four forest types, is predicted to decrease by about 5.66%. Dry forest and spiny bush are also predicted to decline in response to unmitigated climate change. Transitional forest may actually increase by as much as 5.24%, but this gain will almost certainly come at the expense of other forest types.

We expected our model to show that mitigating climate change would result in net forest gain. Surprisingly, our results suggest entirely the opposite. Forest occurrence will decrease by up to 5.84%, even with efforts to mitigate climate change. This is because global temperatures are forecast to increase under both mitigated and unmitigated scenarios.

These predicted declines are in addition to the huge losses of forest already caused by ongoing deforestation throughout the island.

It looks as if the damage has already been done.

Climate change, a major threat

The results of our research highlight that climate change is indeed a major threat to Madagascar’s forests and likely other ecosystems worldwide. These findings are deeply concerning for the survival of Madagascar’s animals and plants, many of which depend entirely on forest habitat.

Not only will climate change decrease the size of existing forests, changes in temperature and rainfall will also affect the amount of fruit that trees produce.

A Lemur on tree in the forest. — Madagascar lemurs and other animal and plant species may become extinct if the forests disappear.
Rijasolo/AFP

Many of Madagascar’s animals, such as its lemurs, rely heavily on fruit for food. Changes in fruit availability will have serious impact on the health, reproductive success and population growth of these animals. Some animals may be able to adapt to changes in climate and habitat, but others are very sensitive to such changes. They are unlikely to survive in a hot, arid environment.

This will also have serious knock-on effects for human populations that depend on forests and animals for eco-tourism income. Approximately 75% of Madagascar’s population depends on the forest and subsistence farming for survival, and the tourism sector contributes over US$600 million towards the island’s economy annually.

To ensure that Madagascar’s forests survive, immediate action is needed to end deforestation, protect the remaining patches of forest, replant and restore forests, and mitigate global carbon emissions. Otherwise these remarkable forests will eventually disappear, along with all the animals and plants that depend on them.

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This blog is written by Daniel Hending, Postdoctoral Research Assistant Animal Vibration Lab, University of Oxford and Cabot Institute for the Environment member Marc Holderied, Professor in Sensory Biology, University of Bristol. This article is republished from The Conversation under a Creative Commons license. Read the original article.

Marc Holderied

Exposing people to likely disinformation campaigns about bushfire causes will help inoculate them. JASON O’BRIEN/AAP

Australia’s recent bushfire crisis will be remembered for many things – not least, the tragic loss of life, property and landscape. But one other factor made it remarkable: the deluge of disinformation spread by climate deniers.

As climate change worsens – and with it, the bushfire risk – it’s well worth considering how to protect the public against disinformation campaigns in future fire seasons.

So how do we persuade people not to be fooled? One promising answer lies in a branch of psychology called “inoculation theory”. The logic is analogous to the way a medical vaccine works: you can prevent a virus spreading by giving lots of people a small dose.

In the case of bushfire disinformation, this means exposing, ahead of time, the myths most likely to be perpetrated by sceptics.

Bushfire bunkum

Disinformation can take many forms, including cherry-picking or distorting data, questioning of the scientific consensus by presenting fake experts, and outright fabrication.

On the issue of bushfires in Australia, there is little scientific doubt that human-caused climate change is increasing their magnitude and frequency. But spurious claims on social media and elsewhere of late sought to muddy the waters:

bots and trolls disseminated false arson claims which downplayed the impact of climate change on the bushfires
NewsCorp reported more than 180 arsonists had been arrested “in the past few months”. The figure was a gross exaggeration and distorted the real numbers
The misleading arson claim went viral after Donald Trump Jr, the president’s son, tweeted it. A UK government minister, Heather Wheeler, also repeated the false claim in the House of Commons
NSW Nationals leader John Barilaro, among others, wrongly suggested a lack of hazard reduction burning – the fault of the Greens – had caused the fires
Conservative commentators claimed the 2019-20 bushfires were no worse than those of the past.

Where will it go next?

Climate science clearly indicates Australia faces more dangerous fire weather conditions in the future. Despite this, organised climate denial will inevitably continue.

Research has repeatedly shown that if the public knows, ahead of time, what disinformation they are likely to encounter and why it is wrong, they are less likely to accept it as true.

This inoculation involves two elements: an explicit warning of an impending
attempt to misinform, and a refutation of the anticipated disinformation.

For example, research has shown that if people were told how the tobacco industry used fake experts to mislead the public about the health risks of smoking, they were less likely to be misled by similar strategies used to deny climate change.

It is therefore important to anticipate the next stage of disinformation about the causes of bushfire disasters. One likely strategy will be to confuse the public by exploiting the role of natural climate variability.

This tactic has been used before. When natural variability slowed global warming in the early 2000s, some falsely claimed that global warming “had stopped”.

Of course, the warming never stopped – an unexceptional natural fluctuation merely slowed the process, which subsequently resumed.

Natural climate variability may bring the occasional mild fire season in future. So let’s arm ourselves with the facts to combat the inevitable attempts to mislead.

Here are the facts

The link between human-caused climate change and extreme weather conditions is well established. But natural variability, such as El Niño and La Niña events in the Pacific Ocean may at times overshadow global warming for a few years.

The below video illustrates this. We used historical data from Adelaide to project the expected incidence of extreme heatwaves for the rest of the century, assuming a continued warming trend of 0.3℃ per decade.

The top panel shows the distribution of all 365 daily maximum temperatures for a year, with the annual average represented by the vertical red line. As the years tick over, this distribution is moving up slowly; the red line increasingly diverges from the average temperature observed before the climate started changing (the vertical black line).

The bottom panel shows the expected incidence of extreme heatwaves for each year until 2100. Each vertical line represents an intense heatwave (five consecutive days in excess of 35℃ or three days in excess of 40℃). Each heatwave amplifies the fire danger in that year.

The analysis in the video clarifies several important aspects of climate change:

the number and frequency of extreme heatwaves will increase as the climate continues to warm
for the next few decades at least, years with heatwaves may be followed by one or more years without one
the respite will only be brief because the inexorable global warming trend makes extreme fire conditions more and more inevitable.

Looking ahead

When it comes to monster bushfire seasons, the link to climate change is undeniable. This season’s inferno is a sign of worse to come – even if it doesn’t happen every year.

Educating the public on climate science, and the tactics used by disinformers, increases the chance that “alternative facts” do not gain traction.

Hopefully, this will banish disinformation to the background of public debate, paving the way for meaningful policy solutions.

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This blog is written by Cabot Institute member Professor Stephan Lewandowsky, Chair of Cognitive Psychology, University of Bristol and John Hunter, University Associate, Institute for Marine and Antarctic Studies, University of Tasmania. This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Climate change is threatening Madagascar’s famous forests – our study shows how serious it is