There’s nothing subtle about this deadly consequence of global warming.
[Pexels]
While the recent record-breaking temperatures in Europe have grabbed the headlines, it’s worth remembering that such record-shattering heatwaves are nothing new to other regions of the planet. And many of those regions are fast approaching a grim reality: heat events that will overwhelm the body’s ability to function.
Once this wetbulb temperature threshold is crossed, the air is so full of water vapour that sweat no longer evaporates. Without the means to dissipate heat, our core temperature rises, irrespective of how much water we drink, how much shade we seek, or how much rest we take. Without respite, death follows – soonest for the very young, elderly or those with pre-existing medical conditions.
Wetbulb temperatures of 35°C have not yet been widely reported, but there is some evidence that they are starting to occur in Southwest Asia. Climate change then offers the prospect that some of the most densely populated regions on Earth could pass this threshold by the end of the century, with the Persian Gulf, South Asia, and most recently the North China Plain on the front line. These regions are, together, home to billions of people.
Tom Matthews, Climate Scientist, Loughborough University, The Conversation.
Matthews goes on to warn of “grey swan” events (read his research here, via Nature Climate Change), where overwhelming heat and moisture is coupled with mass power outages triggered by anthropomorphic global warming-boosted extreme weather events to leave vast populated regions physically unable to keep cool.
While many effects of climate change may seem subtle or “something for future generations to worry about,” this extreme situation will happen sooner rather than later, and as Matthews discusses, it has probably already been experienced.
Any debate about the realities of climate change is a distant dot in the rear-view mirror, and, according to a recent study, the scientific consensus that humans are driving global warming has passed 99 percent. (In reality, the consensus that humans are causing the planet to heat up has been an overwhelming majority for years, likely decades.)
Sadly, scientific consensus isn’t enough to stymie the emissions of greenhouse gasses—if it was, the oil rigs and coal mines would have been shut down years ago. It’s the human disposition for greed and myopic politics that will turn this once ecologically-diverse planet into an increasingly inhospitable place for humans to thrive.
The pushback has been political rather than scientific. In the US, the rightwing thinktank the Competitive Enterprise Institute (CEI) is reportedly putting pressure on Nasa to remove a reference to the 97% study from its webpage. The CEI has received event funding from the American Fuel and Petrochemical Manufacturers and Charles Koch Institute, which have much to lose from a transition to a low-carbon economy.
Policy makers who claim to be “skeptical” about the overwhelming scientific consensus that humans are causing global warming aren’t necessarily uneducated fools. They simply do not care. Democracy has long been hijacked by special interest groups and corporations that care little about the future health of the environment and society. In the long run, their belligerent self-interest will undercut their bottom line. It won’t be long until our carbon-driven economy will collapse under the weight of relentless impacts caused by the continued burning of fossil fuels.
It’s the ultimate self-own, and it’s a shame they’ll take us with them.
The space exploration industry is booming, which is an encouraging sign for our future. But some pundits are arguing that rocket launches will exacerbate global warming.
A time-lapse photograph of a SpaceX launch at night [SpaceX]
When so many people, especially those in charge, seem so cavalier about the impact of global warming and climate change on our planet, it’s refreshing to see a perspective that worries about what we’re doing to our environment. Unfortunately, when that perspective focuses on a tiny contributor and seems to lack the understanding of what it criticizes, it needs to be called out. A number of pundits looked at the exploding private space industry and have grown concerned that rocket launches we will inject too much greenhouse gas into the atmosphere, exacerbating global warming and the attendant problems that come with it. And while it’s true that rocket fuel is far from clean, releasing plenty of unwanted chemicals into the atmosphere as it burns, we have to keep the big picture in mind.
When it comes to launching things into space, there aren’t that many alternatives to rockets and their toxic fuel. You can’t use an ion drive or any of the other seemingly sci-fi but realistic propulsion methods for traveling to other worlds and solar systems. Earth’s gravity and atmospheric pressure at sea level are very different from the vacuum of the cosmos where the tiniest push can really add up in the long term. The only way to get tons of supplies and machinery into orbit and beyond is through controlled explosions harnessed by rockets. There is simply no other way currently feasible, and there won’t be until we figure out how to build giant electromagnetic railguns, or how to harness antimatter, although that would come with a high risk of exposure to gamma radiation.
We could conceivably launch human crews in single stage to orbit planes, but their spacecraft are going to have to rely on good old-fashioned rocketry. That said, however, the plan is not to simply keep launching things from earth with no regard to the pollution thousands of rockets launched every year would cause. Launching payloads from Earth is expensive, both financially and energetically, so ideally, we would want to launch them from somewhere else. We would want to take off from the Moon or asteroids, somewhere where the gravity is in a fraction of what it is on our world, and we could use the same engines to propel anywhere between six and a hundred times the cargo. This is what we mean by infrastructure for space exploration. Forget about turning Earth into a giant launchpad. The ideal gateway to the rest of the solar system is the Moon.
Lacking an atmosphere, the Moon doesn’t particularly care how toxic the fuel is or how much greenhouse gas each launch produces. For all intents and purposes, the moon is a harsh and the radioactive wilderness with no environment to conserve. The same goes for asteroids we want to use as refueling stations, which are simply chunks of radiation-battered rock and metal floating through space we could harvest for fuel and building materials by using, of all things, steam powered asteroid-hopping robots. So, while it’s understandable to worry about the carbon footprint of everything that we do, considering the current inaction by so many on pressing climate issues, it’s important to keep things in perspective when doing so. If global warming continues apace, it won’t be thanks to rockets. It will be thanks to stubborn clinging to fossil fuels across the world and pollution from heavy industry and manufacturing.
If we were to push for serious investments in green energy, which is thankfully something that’s already happening, rocket launchers wouldn’t even be a blip on our carbon radar. Before we start asking ourselves how much carbon dioxide a SpaceX Falcon Heavy releases, and how many greenhouse gases it saves by reusing its booster cores, we need to ask ourselves how many coal plants are still powering cities and why, and what it will take to switch them over to clean, renewable sources. Otherwise, we’re doing the equivalent of trying to pay off the national debt by scrimping and saving on how many pencils public school teachers are allowed to get from their school districts. Which would be a funny analogy if it wasn’t true.
Don’t forget your spacesuit: Complex lifeforms, such as humans, would not survive on many of the worlds we thought would be interstellar tropical getaways
[Pixabay]
Worlds like Earth may be even rarer than we thought.
We live on a planet that provides the perfect balance of ingredients to support a vast ecosystem. This amazing world orbits the Sun at just the right distance where water can exist in a liquid state—a substance that, as we all know, is an essential component for our biology to function. Earth is also an oddball in our solar system, being the only planet where these vast oceans of liquid water persist on its surface, all enshrouded in a thick atmosphere that provides the stage for a complex global interplay of chemical and biological cycles that, before we industrialized humans came along, has supported billions of years of uninterrupted evolution and biological diversity.
Humans, being the proud intelligent beings that we profess to be, are stress-testing this delicate balance by pumping an unending supply of carbon dioxide into the atmosphere. Being a potent greenhouse gas, we’re currently living through a new epoch in our planet’s biological history where an exponential increase in CO2 is being closely followed by an increase in global average temperatures. We are, in effect, altering Earth’s habitability. Well done, humans!
While this trend is a clear threat to the sustainability of our biosphere, spare a thought for other “habitable” worlds that may appear to have all the right stuff for complex lifeforms to evolve, but toxic levels of the very chemicals that keep these worlds habitable has curtailed the possibility of complex life from gaining a foothold.
Welcome to the Not-So-Habitable Zone
Habitable zone exoplanets are the Gold Standard for exoplanet-hunters and astrobiologists alike. Finding a distant alien world within this zone—a region surrounding any star where it’s not too hot and not too cold for water to exist on its surface, a region also known as the “Goldilocks Zone” for obvious reasons—spawns a host of questions that our most advanced telescopes in space and on the ground try to answer: Is that exoplanet Earth-sized? Does it have an atmosphere? What kind of star is it orbiting? Does its system possess a Jupiter-like gas giant? These questions are all trying to help us understand whether that world has the Earthly qualities that could support hypothetical extraterrestrial life.
(Of course, there’s the debate as to whether all life in the universe is Earth-life-like, but as we’re the only biological examples that we know of in the entire galaxy, it’s the best place to start when pondering what biological similarities extraterrestrial life may have to us.)
The habitable zone for exoplanets is a little more complicated than simply the distance at which they orbit their host stars, however. Greenhouse gases, such as carbon dioxide, can extend the area of a star’s habitable zone. For example: If an atmosphere-less planet orbits beyond the outermost edge of its habitable zone, the water it has on its surface will remain in a solid, frozen state. Now, give that planet an atmosphere laced with greenhouse gases and its surface may become warm enough to maintain the water in a liquid state, thereby boosting its habitable potential.
But how much is too much of a good thing? And how might this determination impact our hunt for truly habitable worlds beyond our own?
In a new study published in the Astrophysical Journal, researchers have taken another look at the much-coveted habitable zone exoplanets to find that, while some of the atmospheric gases are essential to maintain a temperature balance, should there be too much of the stuff keeping some of those worlds at a habitable temperature, their toxicity could curtail any lifeforms more complex than a single-celled microbe from evolving.
“This is the first time the physiological limits of life on Earth have been considered to predict the distribution of complex life elsewhere in the universe,” said Timothy Lyons, of the University of California, Riverside, and director of the Alternative Earths Astrobiology Center.
“Imagine a ‘habitable zone for complex life’ defined as a safe zone where it would be plausible to support rich ecosystems like we find on Earth today,” he said in a statement. “Our results indicate that complex ecosystems like ours cannot exist in most regions of the habitable zone as traditionally defined.”
Toxic Limits
Carbon dioxide is an essential component of our ecosystem, particularly as it’s a greenhouse gas. Acting like an insulator, CO2 absorbs energy from the Sun and heats our atmosphere. When in balance, it stops too much energy from being radiated back out into space, thereby preventing our planet from being turned into a snowball. Levels of CO2 have ebbed and flowed throughout the biological history of our planet and it has always been a minor component of atmospheric gases, but its greenhouse effect (i.e. the atmospheric heating effect) is extremely potent and the human-driven 400+ppm levels are causing dramatic climate changes that modern biological systems haven’t experienced for millions of years. That said, the CO2 levels required to keep some “habitable” exoplanets in a warm enough state would need to be a lot more concentrated than the current terrestrial levels, potentially making their atmospheres toxic.
“To sustain liquid water at the outer edge of the conventional habitable zone, a planet would need tens of thousands of times more carbon dioxide than Earth has today,” said lead author Edward Schwieterman, of the NASA Astrobiology Institute. “That’s far beyond the levels known to be toxic to human and animal life on Earth.”
In the blue zone: some of the known exoplanets that fall within the habitable zones of their stars may have an overabundance of CO (yellow/brown), at a level that is toxic to human life. Likewise, the more CO2 (from blue to white) will become toxic at a certain point. The sweet-spot is where Earth sits, with Kepler 442b (if it has a habitable atmosphere) coming in second [Schwieterman et al., 2019. Link to paper]
From their computer simulations, to keep CO2 at acceptable non-toxic levels, while maintaining planetary habitability, the researchers realized that for simple animal life to survive, the habitable zone will shrink to no more than half of the traditional habitable zone. For more complex lifeforms—like humans—to survive, that zone will shrink even more, to less than one third. In other words, to strike the right balance between keeping a hypothetical planet warm enough, but not succumbing to CO2 toxicity, the more complex the lifeform, the more compact the habitable zone.
This issue doesn’t stop with CO2. Carbon monoxide (CO) doesn’t exist at toxic levels in Earth’s atmosphere as our hot and bright Sun drives chemical reactions that remove dangerous levels of the molecule. But for exoplanets orbiting cooler stars that emit lower levels of ultraviolet radiation, such as those that orbit red dwarf stars (re: Proxima Centauri and TRAPPIST-1), dangerous levels of this gas can accumulate. Interestingly, though CO is a very well-known toxic gas that prevents animal blood from carrying oxygen around the body, it is harmless to microbes on Earth. So it may be that habitable zone exoplanets orbiting red dwarfs could be a microbial heaven, but an asphyxiation hell for more complex lifeforms that have cardiovascular systems.
While it could be argued that life finds a way—extraterrestrial organisms may have evolved into more complex states after adapting to their environments, thereby circumventing the problems complex terrestrial life has with CO2 and CO—if we are to find a truly “Earth-like” habitable world that could support human biology, these factors need to be considered before declaring an exoplanet habitable. And, besides, we might want to make the interstellar journey to one of these alien destinations in the distant future; it would be nice to chill on an extraterrestrial beach without having to wear a spacesuit.
“Our discoveries provide one way to decide which of these myriad planets we should observe in more detail,” said Christopher Reinhard, of the Georgia Institute of Technology and co-leader of the Alternative Earths team. “We could identify otherwise habitable planets with carbon dioxide or carbon monoxide levels that are likely too high to support complex life.”
Earth: Unique, Precious
Like many astronomical and astrobiological studies, our ongoing quest to explore strange, new (and habitable) worlds has inevitably led back to our home and the relationship we have with our delicate ecosystem.
“I think showing how rare and special our planet is only enhances the case for protecting it,” Schwieterman said. “As far as we know, Earth is the only planet in the universe that can sustain human life.”
So, before we test the breaking point of our atmosphere’s sustainability, perhaps we should consider our own existential habitability before its too late to repair the damage of carbon dioxide emissions. That’s the only way that we, as complex (and allegedly intelligent) lifeforms, can continue to ask the biggest questions of our rich and mysterious universe.
The fairing of the Taurus XL rocket upper stage failed to separate correctly in this morning's OCO launch (Vandenberg Air Force Base/NASA)
In the early hours of this morning at 1:55am PST, a carbon dioxide monitoring mission was launched from Vandenberg Air Force Base in California. NASA’s Orbiting Carbon Observatory (OCO) was being carried into a 700 km polar orbit by a Taurus XL rocket. Unfortunately, 12 minutes and 30 seconds into the flight, the rocket upper stage suffered an anomaly, and the fairing failed to separate. Although it appears the rocket attained the desired altitude The vehicle did not attain the desired altitude and the $270 million satellite was doomed, trapped inside the the nose cone. The upper stage fairing was protecting the OCO as it ascended through the atmosphere; once in space it should have separated, peeled off and dropped away. That didn’t happen. Continue reading “Not Just a Satellite: NASA’s Orbiting Carbon Observatory Fails (Update)”
A small environmental impact, Falcon 1 launches in September 2008 (SpaceX)
For every article written about the amazing advances in space vehicle technology, there are two negative comments about the pointlessness of space exploration. “What’s the point?“, “We have war, famine, poverty and human suffering around the world, why invest billions on space?“, “What’s space exploration ever done for me?“. However, today, after I wrote a pretty innocuous article about the awesome SpaceX Falcon 9 rocket being hoisted vertically on the launchpad at Cape Canaveral, I get a comment (anonymous, naturally) starting off with, “This launch and others like it should be halted indefinitely until it’s carbon footprint and environmental impact can be accounted for.” The commenter then goes into something about making an environmental assessment, levying SpaceX’s taxes and setting up a board of environmental scientists. Oh please.
On the one hand, I’m impressed by this person’s spirited stand against environmental damage, carbon emissions and global warming, but on the other, this is probably one of the most misplaced environmentalism attacks I have seen to date. There are extremists on both sides of the “green” debate, but the last thing we need is an attack against the only answer we have to fight climate change. And that answer comes in the form of a cigar shaped polluter, blasting into Earth orbit; whether you like it or not, it is a necessary (yet small) evil… Continue reading “Oh No! Rocket Launches Are Bad for the Environment? We’d Better Stay at Home Then”
The Aztecs, affected atmospheric carbon levels? (Getty)
Global warming anyone? I ask as I don’t want to upset anybody. Forget it, I’m going to talk about it anyway.
Climate change is an important subject worthy of debate. But for a debate to develop into something constructive, all sides need to have some scientific merit. Clearly, if we listen to Leo DiCaprio, Al Gore and the world’s carbon-cutting politicians, we might be led to believe we are damaging the environment… hell, we might even be warming the whole planet through carbon emissions! So, strip the Hollywood glamour and political spin from the debate, does the global warming debate have any science linking human activity with increased global temperatures?
In a new study, focusing on Central and South America, scientists have uncovered possibly one of the earliest recorded cases of human-induced climate change, possibly amplifying (or even triggering) the Little Ice Age in Europe throughout the 16th century and beyond… Continue reading “Climate Change, More Human Than We Thought”
Cryosat-2. Resembles something Da Vinci would have designed (ESA)
ESA Cryosat-2 is set for launch in 2009 and it is the second attempt at getting the technology into orbit. Back in 2005, the original CryoSat was lost after a rocket malfunction caused it to fall short of the desired orbit, but much like the Phoenix Mars Lander story (i.e. it rose from the ashes of the lost Mars Polar Lander mission, recycled spare parts and reassembled the robot), Cryosat will fly once more. So what makes this mission so important? Well, it will carry out an essential three-year survey, measuring the thickness of global ice sheets.
But why am I really mentioning it? Like many ESA missions, the designs of their satellites and robots are so cool, and Cryosat-2 is no different. From some angles it looks like a sturdy intergalactic battleship, from others it looks like it was painstakingly designed by Da Vinci. Sometimes it even looks like a flying shed. In my books, that’s one interesting satellite. The science isn’t bad either… Continue reading “CryoSat-2, a Satellite that Looks Like a Shed, Doing Science in the Freezer”
astroengine.com 