extreme temperatures

Canadian wildfires and global emissions

October 14, 2024 By EarthWise Leave a Comment

The wildfires that burned vast amounts of Canada’s boreal forests in 2023 produced enormous amounts of smoke that found its way into American cities, working its way down the eastern seaboard and even producing unsafe air in Florida.

Researchers at Cal Tech and the Jet Propulsion Laboratory analyzed the carbon emissions associated with these fires last year and found that they were greater than those of all but three countries: China, the US, and India.

Boreal forests have historically been a natural defense against climate change by storing carbon in trees rather than adding carbon dioxide to the atmosphere. The fires in Canada, fueled by hot and dry weather, were extraordinary when compared with historical records. But such fires are likely to be increasingly common as the climate continues to warm.

However, the hot and dry weather that fueled the 2023 fires was exceptional in many ways, involving early snow melt and so-called flash droughts. This year’s fires in Canada are still bigger than average, but so far have not been as destructive as last year’s.

Canada has been warming at about twice the global rate. The extreme temperatures last summer were a major factor in the fueling of the fires, which burned an area almost the size of Florida.

Forests absorb about a quarter of global carbon emissions, but the increasing frequency and intensity of fires are calling into question their ability to continue to do so. Parts of the Canadian forests are not regrowing after fires as they have in the past, partly because blazes burn trees so frequently and intensely.

**********

Web Links

Canada’s Wildfires Were a Top Global Emitter Last Year, Study Says

Photo, posted June 8, 2023, courtesy of the Metropolitan Transportation Authority via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Marine Heat Waves | Earth Wise

August 17, 2023 By EarthWise Leave a Comment

In late July, the ocean temperature measured in Florida Bay, between the southern end of the Florida mainland and the Florida Keys, was 101.1 degrees Fahrenheit, a possible world record for sea surface temperature. There is no official record keeping for ocean temperatures, but the highest previous reading ever reported was 99.7 degrees in the middle of Kuwait Bay in 2020.

What is going on is a marine heat wave and marine heat waves can last for weeks, months, or even years. The current Gulf of Mexico marine heat wave has been present for several months, beginning in February or March. Experimental forecasts by the National Oceanic and Atmospheric Administration say the extreme ocean temperatures in the area may persist through at least October.

The ocean absorbs 90% of the excess heat associated with global warming. Therefore, marine heat waves all over the planet are becoming warmer over time. The current marine heat wave would likely have occurred even without climate change, but because of it, the event is extraordinarily warm.

Marine heat waves cause stress to corals and other marine ecosystems. Exposure to extreme temperatures for long periods of time causes corals to eject the algae that live inside of them, resulting in white or pale coral. This coral bleaching leaves the coral without food and will ultimately kill it.

In general, extreme heat can be destructive and deadly for marine ecosystems. A massive marine heat wave known as “the Blob” took hold in 2013-2016 in the northeastern Pacific Ocean and led to an ecological cascade of fishery collapses, toxic algal blooms, and record numbers of humpback whale entanglements.

**********

Web Links

The ongoing marine heat waves in U.S. waters, explained

Photo, posted December 25, 2016, courtesy of Paul Asman and Jill Lenoble via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Heatwaves And Bird Populations | Earth Wise

July 28, 2022 By EarthWise Leave a Comment

The increased occurrence and intensity of heatwaves around the world is affecting most living things. Heatwaves can be lethal for warm-blooded animals – including people – but the behavioral and physiological effects of sub-lethal heat have not been extensively studied. Heat that doesn’t kill animals can still impact their ability to adapt and thrive as the climate changes.

Researchers at the University of Tennessee in Knoxville recently published a new study that examined how heat impacts the behavior and physiology of Zebra finches. They exposed the birds to a four-hour heat challenge, similar to what wild birds might experience during a hot summer afternoon. They used Zebra finches because these songbirds experience extreme temperature fluctuations in their native Australia.

The team measured heat effects on thermoregulatory behavior, how heat alters gene activity in tissues critical to reproduction, and how heat affects the area of the brain that controls singing. The evidence showed that even sub-lethal heat can change a bird’s ability to reproduce both from the functioning of its reproductive system and its motivational circuits for mating behavior.

The researchers found that some individual birds were better able to minimize the physiological effect of heat, for example by adjusting their behavior to dissipate heat. Some individuals and even some species are likely to be able to adapt to increasingly extreme temperatures.

Global bird populations have been dramatically declining over the past few decades. Previous studies have shown that birds sing less during heatwaves. Based on the new study, it appears that increasing heatwaves may be a potential underlying mechanism for the decline in bird populations.

**********

Web Links

New Research Suggests Heat Waves Could Lead to Avian Population Decline

Photo, posted August 22, 2017, courtesy of Dennis Jarvis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solid State Batteries For Cars | Earth Wise

January 7, 2022 By EarthWise Leave a Comment

Today’s electric cars run on lithium-ion batteries, the same sort that power our phones, computers, and many other consumer electronic devices. These batteries are far superior to the batteries of the past, offering long-life, high-energy density, and recyclable components.

Lithium-ion batteries do have their drawbacks. They may be lighter than older battery technologies, but because the electrolytes in the batteries are liquid, they are still fairly heavy. The huge number of them in an electric car adds up to a considerable amount of weight. In addition, the flammability of the electrolytes can lead to explosions or fires if the batteries are damaged or exposed to extreme temperatures.

Solid-state batteries are an alternative technology that contain a solid electrolyte. Such batteries are lighter, have higher energy density, offer more range, and recharge much more quickly than lithium-ion batteries. They have been used for years in some small devices like cardiac pacemakers, RFIDs, and some wearable devices.

For all these benefits, scaling up production to the level needed to be used in cars is an expensive and challenging endeavor. The hope is that with sufficient effort, the result will be smaller, lighter battery packs for cars that can be charged in minutes and provide extended range.

Nissan Motor Company has recently announced that it is investing $17.6 billion over the next five years towards developing solid-state batteries for cars. No doubt other companies will also be working on the technology.

Lithium-ion batteries have proven to be quite practical for powering vehicles. But if solid-state batteries can meet the challenges of scaled up production, the lithium-ion era might end up being a relatively brief one.

**********

Web Links

Nissan to Spend $18 Billion Developing a Cheaper, More Powerful EV Battery

Photo, posted November 13, 2018, courtesy of FirstEnergy Corp via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Deadly Urban Heat On The Rise | Earth Wise

November 9, 2021 By EarthWise Leave a Comment

According to a new study by the Columbia Climate School, exposure to deadly urban heat has tripled since the 1980s. The increase is the combined result of both rising global temperatures and booming urban population growth.

The study looked at more than 13,000 cities worldwide and found that incidents of extreme heat and humidity have increased dramatically. It defined extreme heat as 30 degrees Celsius on the wet-bulb temperature scale that takes into account the effect of high humidity. In 1983, there were 40 billion person-days under such conditions. By 2016, the number was 119 billion. More specifically, in 2016 1.7 billion people were subjected to such conditions on multiple days.

Sheer urban population growth accounted for two-thirds of the increase, while actual warming contributed a third. Over recent decades, hundreds of millions of people have moved from rural areas to cities, which now hold more than half the world’s population. And because of the urban heat island effect, temperatures in cities are generally higher than in the countryside.

In the United States, about 40 sizable cities have seen rapidly growing exposure to extreme heat, mainly clustered in Texas and the Gulf Coast. Globally, nearly a quarter of the world’s population is affected by the increased incidence of extreme temperatures.

A study last year showed that combinations of heat and humidity literally beyond the limits of outdoor human survival have been popping up around the world. A wet-bulb temperature reading of 30 – equivalent to 106 degrees Fahrenheit on the “real feel” heat index – is the point at which even most healthy people find it hard to function outside for long, and the unhealthy might become very ill or even die.

**********

Web Links

Exposure to Deadly Urban Heat Worldwide Has Tripled in Recent Decades, Says Study

Photo, posted March 5, 2007, courtesy of Michael Phillips via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shielding From Food Waste

May 28, 2018 By EarthWise Leave a Comment

Food waste is one of the most disheartening problems we face. Fully one-third of all food produced globally for human consumption is wasted. Fruits, vegetables and tubers are even worse off: fully half of these things are wasted. It is a loss at an economic, social and environmental level.

Extreme Weather Increasing

May 11, 2018 By EarthWise Leave a Comment

It sure seems like extreme weather is increasingly common: floods, droughts, extreme rainfall, powerful snowstorms, hurricanes and so on. But we tend to focus on recent events and often give them undue emphasis. So, it is reasonable to ask whether extreme weather really is more common these days.