Hot, dusty and on fire: Portugal’s heatwave breaks records
By BARRY HATTON
Saturday, August 4
LISBON, Portugal (AP) — Eight places in Portugal broke local temperature records as a wave of heat from North Africa swept across the Iberian peninsula — and officials predicted the scorching temperatures could get even worse over the weekend.
Temperatures built to around 45 degrees Celsius (113 degrees Fahrenheit) Friday in many inland areas of Portugal, and were expected to peak at 47 C (116.6 F) in some places Saturday. Large sections of Portugal are on red alert on the Civil Protection Agency’s danger scale.
The highest temperature recorded Thursday, when the heat began to rise, was 45.2 C (113.4 F) near Abrantes, a town 150 kilometers (93 miles) northeast of the capital, Lisbon, the country’s weather agency IPMA said.
Portugal’s highest recorded temperature was 47.4 C (117.3 F) in 2003. Emergency services have issued a red alert through Sunday, placing extra services such as medical staff and firefighters on standby.
In Portugal’s southern Alentejo province, streets were largely deserted. Some farmers chose to work during the night instead of in the heat of the day. Beaches around Lisbon, the capital, were packed.
Some 400 firefighters and five water-dropping aircraft, meanwhile, were battling a wildfire in southern Portugal’s Algarve region.
Portugal sees large wildfires every year, although unseasonably cool weather through the end of July has meant fewer blazes in 2018. The government says only about 15 percent of the 10-year average area has been charred so far this year.
Temperatures were being driven higher across the Iberian peninsula by a hot air mass moving northward from Africa, which is also bringing dust from the Sahara Desert, meteorologists said. The dust gave the sky a dark yellow hue in some places.
In Spain, heat warnings were also issued for 41 of the country’s 50 provinces as temperatures were expected to reach up to 44 C (111.2 F). Spain’s highest recorded temperature is 46.9 C (116.42 F) in Cordoba, a southern city, in July 2017.
The World Meteorological Organization says continental Europe’s record is 48 C (118.4 F) in Greece in 1977.
In northern Europe, Sweden was still under threat from wildfires, which in recent weeks have extended into the Arctic Circle.
Sweden’s Civil Contingencies Agency warned of “a high risk” for wildfires in central and southern Sweden this weekend because of the continuing dry weather and strong winds.
And over in Britain, an unusually long, torrid summer has taken its toll on the country’s flowers. The supermarket chain Morrisons has begun selling “wonky” flowers that have not developed properly.
The U.K.’s Met Office weather service says July was the country’s third-warmest month in more than a century.
In Moscow, as temperatures rose to close to 30 C (86 F), city authorities announced they were opening hundreds of “cool rooms” where residents could rest amid air conditioning, with water dispensers and medical attendants.
Although that temperature is far below the blazing heat hitting southern Europe, it’s well above the Russian capital’s average August maximum of 23 C (73 F).
Associated Press writers Jill Lawless in London, Jim Heintz in Moscow and Jan M. Olsen in Copenhagen, Denmark, contributed to this report.
Climate change and wildfires – how do we know if there is a link?
August 10, 2018
Distinguished Senior Scientist, National Center for Atmospheric Research
Kevin Trenberth has received funding from the Department of Energy in addition to base funding from the National Science Foundation
Once again, the summer of 2018 in the Northern Hemisphere has brought us an epidemic of major wildfires.
These burn forests, houses and other structures, displace thousands of people and animals, and cause major disruptions in people’s lives. The huge burden of simply firefighting has become a year-round task costing billions of dollars, let alone the cost of the destruction. The smoke veil can extend hundreds or even thousands of miles, affecting air quality and visibility. To many people, it has become very clear that human-induced climate change plays a major role by greatly increasing the risk of wildfire.
Yet it seems the role of climate change is seldom mentioned in many or even most news stories about the multitude of fires and heat waves. In part this is because the issue of attribution is not usually clear. The argument is that there have always been wildfires, and how can we attribute any particular wildfire to climate change?
As a climate scientist, I can say this is the wrong framing of the problem. Global warming does not cause wildfires. The proximate cause is often human carelessness (cigarette butts, camp fires not extinguished properly, etc.), or natural, from “dry lightning” whereby a thunderstorm produces lightning but little rain. Rather, global warming exacerbates the conditions and raises the risk of wildfire.
Even so, there is huge complexity and variability from one fire to the next, and hence the attribution can become complex. Instead, the way to think about this is from the standpoint of basic science – in this case, physics.
This year is proving to be another active wildfire season.
Global warming is happening
To understand the interplay between global warming and wildfires, consider what’s happening to our planet.
The composition of the atmosphere is changing from human activities: There has been over a 40 percent increase in carbon dioxide, mainly from fossil fuel burning since the 1800s, and over half of the increase is since 1985. Other heat-trapping gases (methane, nitrous oxide, etc.) are also increasing in concentration in the atmosphere from human activities. The rates are accelerating, not declining (as hoped for with the Paris agreement).
This leads to an energy imbalance for the planet.
The flows of energy through the climate system are schematically illustrated with numbers on the top-of-atmosphere values and net energy imbalance at the surface. Trenberth et al 2009
Heat-trapping gases in the atmosphere act as a blanket and inhibit the infrared radiation – that is, heat from the Earth – from escaping back into space to offset the continual radiation coming from the sun. As these gases build up, more of this energy, mostly in the form of heat, remains in our atmosphere. The energy raises the temperature of the land, oceans and atmosphere, melts ice, thaws permafrost, and fuels the water cycle through evaporation.
Moreover, we can estimate Earth’s energy imbalance quite well: It amounts to about 1 watt per square meter, or about 500 terawatts globally.
While this factor is small compared with the natural flow of energy through the system, which is 240 watts per square meter, it is large compared with all other direct effects of human activities. For instance, the electrical power generation in the U.S. last year averaged 0.46 terawatts.
The extra heat is always the same sign and it is spread across the globe. Accordingly, where this energy accumulates matters.
Tracking the Earth’s energy imbalance
The heat mostly accumulates ultimately in the ocean – over 90 percent. This added heat means the ocean expands and sea level rises.
Heat also accumulates in melting ice, causing melting Arctic sea ice and glacier losses in Greenland and Antarctica. This adds water to the ocean, and so the sea level rises from this as well, rising at a rate of over 3 milimeters year, or over a foot per century.
Global ocean heat content for the top 2000 meters of the ocean, with uncertainty estimates by the pink region.
On land, the effects of the energy imbalance are complicated by water. If water is present, the heat mainly goes into evaporation and drying, and that feeds moisture into storms, which produce heavier rain. But the effects do not accumulate provided that it rains on and off.
However, in a dry spell or drought, the heat accumulates. Firstly, it dries things out, and then secondly it raises temperatures. Of course, “it never rains in southern California” according to the 1970s pop song, at least in the summer half year.
So water acts as the air conditioner of the planet. In the absence of water, the excess heat effects accumulate on land both by drying everything out and wilting plants, and by raising temperatures. In turn, this leads to heat waves and increased risk of wildfire. These factors apply in regions in the western U.S. and in regions with Mediterranean climates. Indeed many of the recent wildfires have occurred not only in the West in the United States, but also in Portugal, Spain, Greece, and other parts of the Mediterranean.
A satellite image of the Carr Fire in California. Drought conditions, in addition to a lot of dead trees and vegetation, are contributing to another year of severe wildfires. NASA
The conditions can also develop in other parts of the world when strong high pressure weather domes (anticyclones) stagnate, as can happen in part by chance, or with increased odds in some weather patterns such as those established by either La Niña or El Niño events (in different places). It is expected that these dry spots move around from year to year, but that their abundance increases over time, as is clearly happening.
How big is the energy imbalance effect over land? Well, 1 Watt per square meter over a month, if accumulated, is equivalent to 720 Watts per square meter over one hour. 720 Watts is equivalent to full power in a small microwave oven. One square meter is about 10 square feet. Hence, after one month this is equivalent to: one microwave oven at full power every square foot for six minutes. No wonder things catch on fire!
Coming back to the original question of wildfires and global warming, this explains the argument: there is extra heat available from climate change and the above indicates just how large it is.
In reality there is moisture in the soil, and plants have root systems that tap soil moisture and delay the effects before they begin to wilt, so that it typically takes over two months for the effects to be large enough to fully set the stage for wildfires. On a day to day basis, the effect is small enough to be lost in the normal weather variability. But after a dry spell of over a month, the risk is noticeably higher. And of course the global mean surface temperature is also going up.
“We can’t attribute a single event to climate change” has been a mantra of climate scientists for a long time. It has recently changed, however.
As in the wildfires example, there has been a realization that climate scientists may be able to make useful statements by assuming that the weather events themselves are relatively unaffected by climate change. This is a good assumption.
Also, climate scientists cannot say that extreme events are due to global warming, because that is a poorly posed question. However, we can say it is highly likely that they would not have had such extreme impacts without global warming. Indeed, all weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be.
In particular, by focusing on Earth’s Energy Imbalance, new research is expected to advance the understanding of what is happening, and why, and what it implies for the future.
The Conversation US, Inc.
Exposure to wildfire smoke: 5 questions answered
December 7, 2017
Richard E. Peltier
Associate Professor of Environmental Health Sciences, University of Massachusetts Amherst
Richard E. Peltier does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
University of Massachusetts Amherst
University of Massachusetts Amherst provides funding as a founding partner of The Conversation US.
Wildfires once again are raging in California – this time in the Los Angeles area, where five fires are currently burning. The fast-moving Thomas fire alone has burned more than 65,000 acres in three days. State agencies are issuing air quality alerts due to wildfire smoke. Atmospheric chemist Richard Peltier explains why smoke from wildfires is hazardous and what kinds of protection are effective.
What substances in wildfire smoke are most dangerous to human health? What kinds of impacts can they have?
Wood smoke contains a mixture of microscopic droplets and particles and invisible gases that spread downwind from the fire source. Surprisingly, relatively few studies have investigated the types of exposures we are now seeing in California. Most studies focus on very controlled laboratory experiments, or forest fire fighters who are working on controlled burning, or exposures people in developing nations experience when they use primitive cook stoves. None of these accurately reflects conditions that Californians are experiencing now.
Wood smoke is a very complicated mixture of material in the air, and much of it is known to affect human health. It comes from lots of different fuel sources, including mature trees, dried leaves, forest litter and, unfortunately, local homes. The emissions vary depending on what material is burning and whether it is smoldering or in flames.
Smoke streams from several fires in Southern California on Dec. 5, 2017. NASA Earth Observatory
For the most part, wildfire smoke is a mixture of carbon monoxide, volatile organic carbon and particles that include alkaline ash, black carbon and organic carbon, which usually contains polyaromatic hydrocarbon, a known cancer-causing agent.
Is a brief exposure, say for a few hours, dangerous, or is smoke mainly a concern if it lingers for days? How does distance from the fire affect risk?
We don’t fully know how the size and length of the dose affect risks, but the longer you are exposed to pollutants from wood smoke, the higher the risk of developing smoke-related illnesses. Short-term exposures to intense smoke can lead to lung and cardiovascular problems in some people, especially if they are already susceptible to these diseases. Longer-term exposure over a few days or weeks increases the risk and the chance of health impacts as your cumulative dose increases.
Smoke tends to become more diluted with distance from the source, but there really isn’t any way to estimate a safe distance where the pollutants are so diluted that they pose no risk. Eventually rainfall will clean all of this pollution from the atmosphere, but that can take days or even weeks. In the meantime, these pollutants can travel thousands of miles. That means air pollution from wildfires may threaten people who are far downwind.
Image of a plume of high-altitude smoke from a forest fire near Alaska, observed in northern Quebec, Canada, more than 2,000 miles away. Richard Peltier, CC BY-ND
How do the worst pollution levels from wildfires in California compare to bad air days in a megacity like Beijing or Mumbai?
The concentrations of pollution in communities downwind of these fires are on par with what we see in rapidly growing cities such as Mumbai and Beijing. But there is an important difference. In California these pollutants affect a relatively small geographic area, and the affected areas can rapidly shift with changing weather patterns. In locations like Mumbai and Beijing, high concentrations are sustained across the entire region for days or even weeks. Everyone in the community has to endure them, and there is no practical escape. For now, though, some Californians are experiencing what it’s like to live in a developing country without strong air pollution controls.
How should people in smoky areas protect themselves? Are there remedies they should avoid?
The most effective way to protect yourself is by staying with friends or family who live far away from the smoke. People who can’t leave the area should close windows and doors, and apply weather sealing if they detect smoke leaking in. Even masking tape can be reasonably effective. But most houses leak outside air indoors, so this strategy isn’t foolproof.
Portable high-efficiency filter devices – often marketed as HEPA – can remove indoor air pollution but often are too small to be effective for an entire house. They are best used in individual rooms where people spend a great deal of time, such as a bedroom. And they can be very expensive.
Products marketed as air fresheners that use odorants, such as scented candles or oil vaporizers that plug into an outlet, do nothing to improve air quality. They can actually make it worse. Similarly, products that “clean” the air using ozone can release ozone into your home, which is very hazardous.
Personal face mask respirators can also be effective, but not the cheap paper or cloth masks that many people in developing countries commonly use. The best choice is an N95-certified respirator, which is designed to protect workers from hazardous exposures on the job.
These masks are made of special fabric that is designed to catch particles before they can be inhaled. Paper masks are meant to protect you from contact with large droplets from someone who might be ill. N95 respirators block particles from entering your mouth and nose. They can be a little uncomfortable to wear, especially for long periods, but are pretty effective, and many retailers sell them.
What else do scientists want to know about wildfire smoke?
We have a pretty good understanding of the pollutants that wildfires emit and how they change over time, but we don’t have a firm grasp of how different health effects arise, who is most susceptible or what the long-term effects may be. It is not easy to predict where and when wildfires will occur, which makes it hard for scientists to evaluate individuals who have been exposed to smoke. Controlled laboratory studies give us some clues about what happens in the human body, but these exposures often are quite different from what happens in the real world.
Wildfire smoke in heavily settled areas like Los Angeles affect thousands of people. We saw similar situations in other cities this year, including Seattle, Portland and San Francisco. And it’s not just a West Coast issue. In late November there were major fires reported in Arkansas, Kansas, Kentucky, Missouri, Oklahoma and Pennsylvania. We need to learn more about how smoke exposure affects people in real-world conditions, during fires and long after they end.
Editor’s note: This is an updated version of an article originally published on Oct. 16, 2017.
The Conversation US, Inc.