Report: Climate Change Boosts Risk of Extreme Wildfires 25%

September 5, 2023 by

A group of scientists used machine learning to quantify empirical relationships between temperature and the risk of extreme daily wildfire growth in California to show the influence of temperature on the risk – and they found that climate change boosts the risk of extreme wildfires 25%.

The report out this week in the journal Nature shows the risk is primarily mediated through climate change’s influence on fuel moisture.

“We use the uncovered relationships to estimate the changes in extreme daily wildfire growth risk under anthropogenic warming by subjecting historical fires from 2003 to 2020 to differing background climatological temperatures and aridity conditions,” the study states.

While they found the influence of global warming on the risk of wildfire growth “varies appreciably on a fire-by-fire and day-by-day basis” depending on whether climate warming pushes conditions past certain thresholds of aridity, warming has boosted the expected frequency of extreme daily wildfire growth by 25% on average relative to preindustrial conditions.

Some portion of the change in wildfire behavior is attributable to climate change.

However, until now, formally quantifying this contribution has been difficult.

Climate Fatalities

A billion people could die from climate catastrophes over the next century, a new study shows.

A recent review of 180 articles on the human death rate of climate change takes into account a rule of thumb called the “1000-ton rule,” under which every thousand tons of carbon that humanity burns is said to indirectly condemn a future person to death, according to a write up in ScienceAlert.

“If you take the scientific consensus of the 1,000-ton rule seriously, and run the numbers, anthropogenic global warming equates to a billion premature dead bodies over the next century,” energy specialist Joshua Pierce from the University of Western Ontario in Canada, told the website.

The study, Quantifying Global Greenhouse Gas Emissions in Human Deaths to Guide Energy Policy, was published in the periodical Energies. It argues that the high death tolls can be attributed to current carbon emissions, and the study calls for a change in energy policies.

“The primary goal of all current energy policies should be to reduce carbon emissions to zero as fast as possible without causing additional deaths and to eliminate any policy that increases emissions or incentives future fossil carbon extraction,” the study states.

Australia Lawsuit

The Australian government agreed to settle a class action lawsuit over an alleged failure to disclose climate change-related risks to investors in the country’s sovereign bonds.

If approved by the federal court, the terms of the settlement would require the government to make a statement acknowledging climate change is a systemic risk that may affect the value of its government bonds, Reuters reported in an article on Insurance Journal this week. The court is expected to hold a hearing on Oct. 11 to decide whether to approve the settlement.

“As an investor, I am pleased with the proposed settlement. This is the first time a country with a AAA credit rating has acknowledged climate change is a systemic risk when talking about risks to government bonds,” reads a statement from Kathleen O’Donnell, who filed the suit in 2020 claiming investors who buy Australian government bonds should be made aware of the risks due to climate change that might make it difficult for Australia to pay back its debt.

O’Donnell was a 23-year-old student when she bought the bonds in 2020, and she argued that Australia could be facing frequent adverse climate events in 2050 by the time her bonds mature. Ratings agencies acknowledge the vulnerability of economies to climate change, they have so far been cautious in quantifying those risks in their ratings exercises because of uncertainties about the likely extent of the damage, Reuters reported.

Climate Change and Hurricanes

Climate change is making hurricanes more intense, and there is evidence that it is causing storms to travel more slowly, enabling them to dump more water in one place.

That’s according to a Reuters article on The Weather Network, Explainer: How climate change is fueling hurricanes.

The article explains that in the past 40 years, the ocean has absorbed roughly 90% of the warming caused by greenhouse gas emissions.

“Much of this ocean heat is contained near the water’s surface. This additional heat can fuel a storm’s intensity and power stronger winds. And this year is particularly bad,” the Reuters article states. “Climate change can also boost the amount of rainfall delivered by a storm. Because a warmer atmosphere can also hold more moisture, water vapor builds up until clouds break, sending down heavy rain.”

A 2022 study in the journal Nature Communications shows that during the 2020 Atlantic hurricane season, climate change increased rainfall rates in hurricane-force storms by 8% to 11%, while NOAA scientists believe hurricane wind speeds could increase by up to 10% at 2C of warming.

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