Connect with us

Science

Climate change likely to cause more severe hurricanes, report suggests – CBC.ca

Published

 on


When it comes to climate change, experts say few things have been as tricky to predict as its impact on hurricanes.

new report in the ScienceBrief Review website published last week now suggests that many regions affected by hurricanes will likely experience storms of greater intensity as a result of Earth’s changing climate. Maximum wind speeds in hurricanes could rise five per cent if the planet warms by 2 C by 2100, the review of more than 90 peer-reviewed studies found.

And that highlights a need for cities and governments — including those in Canada — to plan ahead for a future where they may be dealing with climate issues they have not had to deal with in the past, experts say.

“It’s important that governments look at how you need to adapt to climate change,” said Canadian researcher Corinne Le Quéré, a Royal Society professor of climate change at the University of East Anglia, who edited the report. “Some of these events will occur in places where perhaps they have not seen hurricane-force winds before. And therefore, you need to develop coping measures to have these alert systems.” 

This satellite image shows five hurricanes churning across the Atlantic Ocean in 2020. The 2020 Atlantic hurricane season went down in history for the most named storms observed in a year (30); the most storms to make landfall in the continental United States (12); the most to hit Louisiana (5); and the most storms to form in September (10). (NOAA)

 

The report, which analyzed peer-reviewed literature, was published as part of a series on climate change issues ahead of the United Nations’ COP26 climate conference scheduled for Nov. 1–2 in Glasgow.

In the U.S. and Canada, hurricanes are categorized using the Saffir-Simpson scale that classifies them from a Category 1 to a Category 5.

To put the five per cent potential rise in maximum wind speeds into perspective, a Category 3 hurricane produces sustained wind speeds ranging from 178 to 208 km/h. A Category 5 produces speeds of 252 km/h or higher. Hurricanes from Categories 3 to 5 are considered major or severe hurricanes.

Not a clean-cut story

The impact of climate change on hurricanes has been tricky to quantify because there are many aspects to the system involved in creating and sustaining a hurricane. And it is hard to separate how much of that is caused by natural or man-made reasons. 

The report said the intensity of hurricanes will “probably” increase as a result of climate change, but it is hard to be certain due to several factors, including a lack of historical data. Since 1979, hurricanes of Category 3 or higher have increased by roughly five per cent, but it’s difficult to say how much of a role climate change has played in this.  

“The reason why the picture seems … a bit murky when we present things is because it’s not as clean-cut a story as we have for something like global mean temperature, where we have these clear records going back to the late 1800s,” said Tom Knutson, division leader at the National Oceanic and Atmospheric Administration’s (NOAA) Geophysical Fluid Dynamics Laboratory, who led the review.

A NOAA satellite image showing the remnants of Hurricane Dorian making landfall in Nova Scotia on Sept. 7, 2019. Dorian knocked out power to more than 500,000 customers across the Atlantic provinces. A near-record storm surge was observed in the harbour at Halifax and along the coast of New Brunswick. (NOAA)

 

“But we can contrast that with this case for hurricanes and hurricane activity where, first of all, there are lots of different ways of looking at hurricanes, lots of different metrics, lots of different regions, and things like that. But in no case, really, do we have a comparable confidence to what we have for global mean temperature.”

While the intensity of hurricanes is likely to increase, it’s also important to note that not all of these storms will necessarily reach inland.

Canada should look at hurricane threat

There are more complications with hurricanes. Climate change is warming sea surface temperatures, which help fuel hurricanes. There is also more moisture available to produce and sustain hurricanes, which results in heavier rainfall. 

In addition, research has found that hurricanes are moving towards the North and South poles by roughly 56 kilometres, or about one degree of latitude, per decade and that they are also moving further inland

With the increase in hurricane intensity, greater rainfall volumes, hurricanes that are moving further inland and poleward, countries including Canada may need to evaluate the potential fallout in the future. 

“Certainly Canada should look at whether [hurricanes] are a threat … If they are more intense, then they also have potential to affect bigger areas,” Le Quéré said. “Certainly the changes in the storm tracks and in the weather patterns is something that Canada should be looking at to see if there is a need [to adapt].”

A street is blocked by fallen trees in Halifax on Sept. 8, 2019, after Hurricane Dorian tore through Nova Scotia. (Andrew Vaughan/Canadian Press)

Deanna Hence, an assistant professor at the University of Illinois Urbana-Champaign’s department of atmospheric sciences, said the report highlights the difficulties predicting hurricanes in a changing climate.

“The biggest thing that comes across from this article that is that when it comes to climate change or tropical cyclones, it’s a really complicated set of interactions and a very complicated set of possible impacts,” said Hence, who was not involved in the study.

“Essentially what people want to know is, if you live in a certain part of the world will hurricanes or typhoons or tropical cyclones hurt you more. That’s I think what really the root question comes down to … And the answer is yes, kind of, sort of.”

It’s just exactly how that is the remaining question. But Hence said that it’s time for all stakeholders to start planning ahead, especially in light of already aging infrastructure that may not be able to handle more precipitation, more storm surge or stronger winds associated with hurricanes.

Overall, climatologists agree that more research needs to be done, and that only time will tell how people will be affected.

“Humans are changing the climate system. And so we’re sort of running this experiment, whether we like it or not, this global warming experiment, and we’re going to find out — as we continue along with this trajectory of warming — we’re going to find out how various things do or don’t change,” Knutson said. “We’ll get more information coming as we continue to alter the climate system.”

Let’s block ads! (Why?)



Source link

Continue Reading

Science

India among 11 ‘countries of concern’ on climate change for U.S. spy agencies

Published

 on

Afghanistan, India and Pakistan were among 11 countries singled out by U.S. intelligence agencies on Thursday as being “highly vulnerable” in terms of their ability to prepare for and respond to environmental and societal crises caused by climate change.

In a new National Intelligence Estimate, the Office of the Director of National Intelligence (ODNI) predicts that global warming will increase geopolitical tensions and risks to U.S. national security in the period up to 2040.

Such estimates are broad U.S. intelligence community assessments. Thursday’s report identifies as particular “countries of concern” Afghanistan, India, Pakistan, Myanmar, Iraq, North Korea, Guatemala, Haiti, Honduras, Nicaragua and Colombia. ODNI posted a declassified version online.

Heat, drought, water availability and ineffective government make Afghanistan specifically worrying. Water disputes are also a key geopolitical flashpoint in India and the rest of South Asia.

The report identifies two additional regions of concern to U.S. intelligence agencies. Climate change is “likely to increase the risk of instability in countries in Central Africa and small island states in the Pacific, which clustered together form two of the most vulnerable areas in the world.”

The report notes disparities around global approaches to tackling climate change, saying countries that rely on fossil fuel exports to support their economies “will continue to resist a quick transition to a zero-carbon world because they fear the economic, political, and geopolitical costs of doing so.”

The report also notes the likelihood of increasing strategic competition over the Arctic. It says that Arctic and non-Arctic states “almost certainly will increase their competitive activities as the region becomes more accessible because of warming temperatures and reduced ice.”

It predicts international competition in the Arctic “will be largely economic but the risk of miscalculation will increase modestly by 2040 as commercial and military activity grows and opportunities are more contested.”

 

(Reporting by Mark Hosenball; Editing by Frances Kerry)

Continue Reading

Science

Mining the moon's water will require a massive infrastructure investment, but should we? – Yahoo News Canada

Published

 on


<img class="caas-img has-preview" alt="Building a moon base will require extensive resources and infrastructure. (Shutterstock)” src=”https://s.yimg.com/ny/api/res/1.2/.m2KoEuLN10EA5S4WJVJgg–/YXBwaWQ9aGlnaGxhbmRlcjt3PTk2MDtoPTQyNw–/https://s.yimg.com/uu/api/res/1.2/1uRhQ0.2td5TYJER6DobpA–~B/aD02NDE7dz0xNDQwO2FwcGlkPXl0YWNoeW9u/https://media.zenfs.com/en/the_conversation_canada_501/2d6de465d32ef88321836f92f2c4c30b” data-src=”https://s.yimg.com/ny/api/res/1.2/.m2KoEuLN10EA5S4WJVJgg–/YXBwaWQ9aGlnaGxhbmRlcjt3PTk2MDtoPTQyNw–/https://s.yimg.com/uu/api/res/1.2/1uRhQ0.2td5TYJER6DobpA–~B/aD02NDE7dz0xNDQwO2FwcGlkPXl0YWNoeW9u/https://media.zenfs.com/en/the_conversation_canada_501/2d6de465d32ef88321836f92f2c4c30b”>

Building a moon base will require extensive resources and infrastructure. (Shutterstock)

We live in a world in which momentous decisions are made by people often without forethought. But some things are predictable, including that if you continually consume a finite resource without recycling, it will eventually run out.

Yet, as we set our sights on embarking back to the moon, we will be bringing with us all our bad habits, including our urge for unrestrained consumption.

Since the 1994 discovery of water ice on the moon by the Clementine spacecraft, excitement has reigned at the prospect of a return to the moon. This followed two decades of the doldrums after the end of Apollo, a malaise that was symptomatic of an underlying lack of incentive to return.

That water changed everything. The water ice deposits are located at the poles of the moon hidden in the depths of craters that are forever devoid of sunlight.

Since then, not least due to the International Space Station, we have developed advanced techniques that allow us to recycle water and oxygen with high efficiency. This makes the value of supplying local water for human consumption more tenuous, but if the human population on the Moon grows so will demand. So, what to do with the water on the moon?

There are two commonly proposed answers: energy storage using fuel cells and fuel and oxidizer for propulsion. The first is easily dispensed with: fuel cells recycle their hydrogen and oxygen through electrolysis when they are recharged, with very little leakage.

Energy and fuel

The second — currently the primary raison d’être for mining water on the moon — is more complex but no more compelling. It is worth noting that SpaceX uses a methane/oxygen mix in its rockets, so they would not require the hydrogen propellant.

So, what is being proposed is to mine a precious and finite resource and burn it, just like we have been doing with petroleum and natural gas on Earth. The technology for mining and using resources in space has a technical name: in-situ resource utilization.

And while oxygen is not scarce on the moon (around 40 per cent of the moon’s minerals comprise oxygen), hydrogen most certainly is.

Extracting water from the moon

Hydrogen is highly useful as a reductant as well as a fuel. The moon is a vast repository of oxygen within its minerals but it requires hydrogen or other reductant to be freed.

For instance, ilmenite is an oxide of iron and titanium and is a common mineral on the moon. Heating it to around 1,000 C with hydrogen reduces it to water, iron metal (from which an iron-based technology can be leveraged) and titanium oxide. The water may be electrolyzed into hydrogen — which is recycled — and oxygen; the latter effectively liberated from the ilmenite. By burning hydrogen extracted from water, we are compromising the prospects for future generations: this is the crux of sustainability.

But there are other, more pragmatic issues that emerge. How do we access these water ice resources buried near the lunar surface? They are located in terrain that is hostile in every sense of the word, in deep craters hidden from sunlight — no solar power is available — at temperatures of around 40 Kelvin, or -233 C. At such cryogenic temperatures, we have no experience in conducting extensive mining operations.

Read more: US seeks to change the rules for mining the Moon

Peaks of eternal light are mountain peaks located in the region of the south pole that are exposed to near-constant sunlight. One proposal from NASA’s Jet Propulsion Lab envisages beaming sunlight from giant reflectors located at these peaks into craters.

Black and white image of the moon's surface

Black and white image of the moon’s surface

These giant mirrors must be transported from Earth, landed onto these peaks and installed and controlled remotely to illuminate the deep craters. Then robotic mining vehicles can venture into the now-illuminated deep craters to recover the water ice using the reflected solar energy.

Water ice may be sublimed into vapour for recovery by direct thermal or microwave heating – because of its high heat capacity, this will consume a lot of energy, which must be supplied by the mirrors. Alternatively, it may be physically dug out and subsequently melted at barely more modest temperatures.

Using the water

After recovering the water, it needs to be electrolyzed into hydrogen and oxygen. To store them, they should be liquefied for minimum storage tank volume.

Although oxygen can be liquefied easily, hydrogen liquefies at 30 Kelvin (-243 C) at a minimum of 15 bar pressure. This requires extra energy to liquefy hydrogen and maintain it as liquid without boil-off. This cryogenically cooled hydrogen and oxygen (LH2/LOX) must be transported to its location of use while maintaining its low temperature.

So, now we have our propellant stocks for launching stuff from the moon.

This will require a launchpad, which may be located at the moon’s equator for maximum flexibility of launching into any orbital inclination as a polar launch site will be limited to polar launches — to the planned Lunar Gateway only. A lunar launchpad will require extensive infrastructure development.

In summary, the apparent ease of extracting water ice from the lunar poles belies a complex infrastructure required to achieve it. The costs of infrastructure installation will negate the cost savings rationale for in-situ resource utilization.

Alternatives to extraction

There are more preferable options. Hydrogen reduction of ilmenite to yield iron metal, rutile and oxygen provides most of the advantages of exploiting water. Oxygen constitutes the lion’s share of the LH2/LOX mixture. It involves no great infrastructure: thermal power may be generated by modest-sized solar concentrators integrated into the processing units. Each unit can be deployed where it is required – there is no need for long traverses between sites of supply and demand.

Hence, we can achieve almost the same function through a different, more readily achievable route to in-situ resource utilization that is also sustainable by mining abundant ilmenite and other lunar minerals.

Let us not keep repeating the same unsustainable mistakes we have made on Earth — we have a chance to get it right as we spread into the solar system.

This article is republished from The Conversation, a nonprofit news site dedicated to sharing ideas from academic experts. It was written by: Alex Ellery, Carleton University.

Read more:

Alex Ellery does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Adblock test (Why?)



Source link

Continue Reading

Science

Vikings Settled In North America As Early As 1021, Researchers Say – iHeartRadio

Published

 on


New research has dated Viking ruins in Canada’s Newfoundland to 1021. While archeologists have known that Vikings had settled in North America hundreds of years before European explorers ventured across the Atlantic Ocean and reached the shores of North America, they had never been able to pinpoint exactly when they arrived.

new study published in Nature provides evidence that around 100 men and women settled at L’Anse aux Meadows in Newfoundland 1,000 years ago.

“This is the first time the date has been scientifically established,” said archaeologist Margot Kuitems, a researcher at the University of Groningen in the Netherlands and the study’s lead author.

“Previously, the date was based only on sagas — oral histories that were only written down in the 13th century, at least 200 years after the events they described took place,” she said.

In order to build their new settlement and repair their ships, the Vikings had to cut down trees in the area. The researchers noted that a burst of cosmic radiation, possibly from a solar storm, hit the Earth in the year 993. Evidence of the storm can be found in tree rings, and researchers used that as a starting date to count the rings on the felled trees. After examining three different pieces of wood, they determined all three were cut down in 1021 using metal tools.

Researchers believe that the Vikings only stayed there for between three and 13 years before they returned to Greenland. The study authors are planning to continue their work and determine exactly how long the Vikings were at L’Anse aux Meadows.

Adblock test (Why?)



Source link

Continue Reading

Trending