Category: Possible Futures

In the midst of our summer living with COVID-19, a novel virus that attacks our respiratory system, and with people in our streets protesting excessive police force, literally wearing face masks bearing the phrase, “I can’t breathe,” it may not be surprising that I have been reflecting on the subject of respiration as it relates to Our Earth’s atmosphere.

As I write this, Our Earth’s atmosphere contains 413.5 ppm (0.04135%) CO₂, and most of this blog is concerned with how changes in that small percentage control Our Earth’s energy balance and climate. But a far greater percentage, 20.9%, is molecular oxygen (O₂), and of course this is vital to every breath we take.

Have you recently thought about why we breathe O₂ and exhale CO₂? How Our Earth’s atmosphere came to contain O₂ in the first place?

It’s a fascinating story. In fact, it has been persuasively argued by many that the transition in Our Earth’s atmosphere I will describe, known as the Great Oxidation Event (GOE) or, sometimes, the “Oxygen Crisis,” is the single most momentous, impactful event ever to occur in Earth’s history. You see, Our Earth is about 4.5 billion years old and, for about half its life, there was no oxygen in the atmosphere. Zero.

“Try to imagine something so profound, so fundamental, that it changed the whole world. Think of something so revolutionary, that it forever changed the chemistry of the atmosphere, the chemistry of the oceans and the nature of life itself.”

–Prof. Donald Canfield, geologist, University of Southern Denmark, writing about the GOE in his book, Oxygen: A Four Billion Year History

Life got started on Our Earth without free oxygen. And it didn’t take long for it to get started, in geological terms. In fact, life got started on Our Earth just about 500 million years after its formation (maybe a bit earlier or a bit later). The required ingredients for life, at least life as we know it (based on carbonaceous DNA) seem to be hydrocarbon molecules and water in which they can dissolve. And life got started on Our Earth not long at all after the formation of its water oceans 4.4 billion years ago.

So how do things live without oxygen? With some effort (and an expensive high-pressure submersible), we can still visit life forms on Earth much like the earliest ones that appeared. Like they did then, they exist in the deep oceans, near hydrothermal vents, volcanically active regions of the ocean floor where seawater co-mingles with mineral-rich magma and becomes superheated creating jets of mineral-rich steam. In the deep ocean, there is no oxygen and no light, and conditions are much like they were in the deep oceans of early Earth. The base of the food chain is formed by colorless bacteria that decorate the seafloor like fluffy snow. (Color has no use in the darkness there, so it hasn’t evolved.)

“Do you get claustrophobic?” the man asked. “No, not at all,” I lied. “Good,” he replied, “and whatever you do, don’t touch the red handle. That’s used only in emergencies.”

-Conversation between Prof. Canfield and the pilot of the deep-diving submersible Alvin, preparing to dive roughly a mile under the ocean to explore a preserved hydrothermal vent powered ecosystem containing organisms similar to the first living things on Earth, as recounted in Prof. Canfield’s book, Oxygen: A Four Billion Year History

They are methanogens, single-celled bacteria that derive their energy by combining hydrogen gas and carbon dioxide, both present in hydrothermal vent steam, to make methane and water. Here is their respiration equation, the chemical equation by which they derive energy to grow:

There’s no oxygen in their respiration equation, because there wasn’t any to be had. These bacteria are also from a category of bacteria called autotrophs, which means, by a set of more complex chemical equations I won’t get into here, they can produce all the mass they need to build themselves — carbohydrates, fats, etc. — straight from carbon dioxide and hydrogen. They work with simple stuff, because simple stuff was all there was when they got started. By observing methanogens, you can see the bare minimum required to make what we call life. You need a way to harness energy (respiration), a way to use that energy to transform stuff in your environment into whatever you’re made of, and (at least for all life we know of) water, which is the medium in which all these chemical transformations happen.

Other simple bacteria co-existed with methanogens on early Earth, living off their dead bodies and off sulfur compounds also issuing from the hydrothermal vents. But, by about 3.5 billion years ago, the random machinations of evolution (and about 500 million years of time) had made a significant innovation: Earth’s first form of photosynthesis. Anoxygenic phototrophs had evolved tiny pigment-driven bio-machines that could use light energy directly from the sun to combine hydrogen sulfide and carbon dioxide in the atmosphere, making their own biomass:

In any sunlit and wet part of the Earth, life no longer had to settle for eking out just 134 kilojoules of energy for every mole of CO₂ and 4 moles of H₂ it could find, then use that bit of energy to do other reactions to make itself. In fact, these little guys had, at a basic level, the same chemical equation for energy and mass building. And, in any sunlit part of the Earth, light energy was abundant. While the early methanogens and their cohorts slummed it near rare, mineral rich hydrothermal vents, the anoxygenic phototrophs inherited the entire wet, sunlit surface of the planet.

In short, life was good. If only hydrogen sulfide were a little more abundant. I mean, volcanoes were erupting, but not, like, every day. So evolution kept at it… About a billion years went by…

Then boom! Some little upstart cyanobacteria (otherwise known as blue-green algae) developed modern photosynthesis. For a billion years of random experimentation, the equation only looks a little bit different:

We’re still using light to form cell mass directly but, oh my! We don’t need a whiff of H₂S here and a whiff of H₂S there. The fuel is carbon dioxide and … water. We’re floating in food! Life was easy, and now in any sunlit, wet part of the Earth it was growing like crazy. But notice the key byproduct of this new respiration equation: oxygen.

So the now dominant blue-green algae spread across the globe, blithely spewing oxygen. This went on for about a billion years until, about 2.5 billion years ago, their waste oxygen began rapidly building up in the atmosphere. This was the Great Oxidation Event, arguably the most transformative period in Our Earth’s history.

For example, it led directly to you and me and to other complex, multi-cellular life, who learned to use the oxygen as part of aerobic respiration, the most energetically powerful respiration equation yet discovered by evolution:

If you compare the amount of energy generated by our oxygen-powered respiration equation with that of the humble methanogens that started life on Our Earth (above), you see that this is a luxurious amount of energy — over 3 and a half times as much as methanogens can produce! This plentiful energy made complex life possible, and powers the energy-hungry brain with which you’re reading this.

So the success of the oxygen-producing cyanobacteria transformed Our Earth’s atmosphere, setting in motion the Great Oxidation Event that put the oxygen in the air that makes life possible for us lucky humans. What a success story! Except, here’s the rub.

IT WAS A LIFE-ENDING DISASTER FOR ALMOST ALL SPECIES OF THE CYANOBACTERIA THAT DID IT, AND ALMOST ALL OTHER LIFE ON EARTH AT THE TIME.

To almost all life on Earth back then, oxygen was a toxic poison. The same hyped-up chemistry that makes oxygen reactions so energetic makes oxygen highly reactive with, well, everything life is made of. For example, it oxidizes, degrades, and wrecks the very DNA that contains the blueprints for life. Also, further changes in the atmosphere occurred. The newly present oxygen oxidized methane (a potent greenhouse gas) in the atmosphere to carbon dioxide (a less potent greenhouse gas). This caused geologically rapid global cooling, resulting in a Snowball Earth that lasted for 300 million years.

The Great Oxidation Event wrought a mass extinction of almost everything living on the planet. When the evolutionary dust settled, the few surviving species had evolved protections that enabled them to live in an oxygenated world. For example, sexual reproduction is an evolutionary invention that repairs oxidation errors in DNA each generation. But that’s another story.

So that’s the story of how we came to breathe oxygen. And how complex life came to flourish across Our Earth’s seas and land, sustained by a virtuous balance of producers that harvest energy from the sun, consuming carbon dioxide and giving off oxygen as a waste product, and eaters (like us) that eat the producers, breathe their waste oxygen, and give off carbon dioxide as a waste product.

But it’s not that simple, is it? Because, unlike other living things, we have developed a civilization. And our civilization has its own respiration equation that greatly amplifies the energy available to us by consuming the buried remains of long-dead plants and animals that have accumulated over the millions of years in this story.

Unlike your personal aerobic respiration equation, our civilization’s respiration equation is returning to the atmosphere carbon dioxide not from plants growing now, but from ancient (fossil) plants. So that carbon dioxide is not part of the virtuous cycle that has governed our atmosphere’s composition since we evolved as a species. The waste CO₂ is building up in the atmosphere, and quickly.

Our success as a species is transforming the composition of Our Earth’s atmosphere on a geologically rapid timescale.

Sound familiar?

“The GOE makes it clear that, at an earlier point in Earth’s history, life fully and completely changed the course of planetary evolution. It shows us that what we are doing today … is neither novel nor unprecedented. But it also tells us that changing the planet may not work out well for the specific forms of life that caused the change.”

–Dr. Adam Frank, astrophysicist, in his book, Light of the Stars

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Thoughts on this cautionary tale during COVID

COVID-19 reminds us of some valuable things. It reminds us that the routines and luxuries of our lives should not be taken for granted. It reminds us that many of the things we count on in our daily lives — from food and water to the mail — rest on complex systems of civilization we have created. And it reminds us that those systems are more fragile than we are used to thinking.

As all of us, regardless of wealth and status, are stalked by a virus that doesn’t read our resumes or care about our bank account balances, COVID-19 reminds us that we are all in this together. In sundry and crucial ways, we count on each other.

The privations of COVID-19 give us time to think. And I think some time thinking about how we want to come out of this — what kind of human civilization we want to have — would be time well spent. I do not think we should want to “return to normal.” By any objective measure, normal is not working and normal will not remain, well, “normal” for much longer. We are cruising pell-mell into a time period entirely analogous to the Great Oxidation Event, and most scientists who study it believe Our Earth’s 6th mass extinction is already underway.

Unlike the mindless cyanobacteria that caused the Great Oxidation Event, we have these big, oxygen-consuming brains with which to think. Plan. Solve. Create. For example, it would be nice if our civilization’s respiration equation looked less like intensified animal respiration and more like photosynthesis. Of course, this is exactly what the solar panels we’ve created are: synthetic photosynthesis. We’ve already used our big brains to develop most of the solutions we need.

We’re just not using our brains to put them to work at nearly the speed required to avoid some really scary outcomes for our species.

So now we have a chance to think about what our “new normal” should look like. It’s a good time to reflect on some assumptions that have been part of our daily routine in our “old normal.” For example, we expect an economy fundamentally based on extraction of valuable resources from Our Earth to continue growing, at an ever faster rate, indefinitely. The assumption is embedded in our daily news, which plays happy music if the stock market grows (typically meaning many of our businesses are growing at a faster rate than they were the same time last year), and otherwise plays sad music.

Hold that thought.

I brew beer at home. It starts by boiling a soup of grain extracts (called “wort”) in a pot. Once the wort is cooled down, you throw a little bit of yeast in. Yeast, a kind of fungi, uses an enzyme called zymase to digest the sugars and carbohydrates in the wort to make ethanol and carbon dioxide.

Several hours after you pitch the yeast in, they enter an exponential growth phase. The beer foams like crazy from all the carbon dioxide being released; you have to have a “blow off” tube on the top of the brewing vessel to let all the foam escape. But the yeasty party is ultimately doomed. The ethanol they are making is poisonous to them, and they are trapped with their toxic ethanol waste inside a closed vessel. Depending on the strain of yeast, once the ethanol reaches between about 5 and 12 percent, the conditions become toxic and most of the yeast die and fall to the bottom of the brewing vessel.

We are doing the same right now. Our civilization has a number of waste products, the most worrisome being fossil carbon dioxide. Which, as ignorant-sounding politicians occasionally remind us, is not “toxic” in the classical sense. But, if allowed to accumulate in our atmosphere unabated, it’s certainly capable of ending our civilization by driving the conditions of our planet (a closed vessel) far outside of those in which we evolved.

“We are in the beginning of a mass extinction, and all you can talk about is money and fairy tales of eternal economic growth. How dare you!”

Greta Thunberg, 16 year old Swedish climate activist, speech at the UN Climate Action Summit, New York, Sept. 23, 2019

So, every batch of beer I brew reminds me that the assumptions underlying our economy are unsustainable. Nothing grows exponentially forever inside a closed system. I certainly don’t have all the answers, but here are some things I think we should be thinking about as we consider what future “normal” we want to have.

• How can we keep the best parts of our way of life (significant personal freedom, the value and efficiency of competition) while making it more sustainable?
• How can we pay ourselves and each other not to do some things we shouldn’t do?
• As we get better and better at automation, how can we pay ourselves and each other not to work as hard at the now automated tasks we used to do ourselves?
• How can we find a healthy balance between the benefits of competition and the divisiveness and inhumanity of an economy that awards most of its benefits to a handful of people who control the increasingly automated capital?
• How can we get past our tendency for xenophobia and start thinking of ourselves as a global species with a shared future?

Of course, it goes without saying that I think we should be investing aggressively in the energy transformation needed to avoid the worst consequences of climate change. According to the International Panel on Climate Change, we have about a decade to be making serious headway on that. For the most part, we have all the solutions we need. The only thing standing in our way is excuses.

And, it seems to me, working together on that (while being necessary for our survival) would also be a good vehicle to start answering the bigger questions.

Related reading:

• “The Mystery of Earth’s Oxygen,” The New York Times, Oct. 3, 2013.
• Oxygen: A Four Million Year History, by Donald E. Canfield.
• Light of the Stars: Alien Worlds and the Fate of the Earth, by Adam Frank.

You’ve probably heard something about the new Special Report, published on October 6, by the International Panel on Climate Change (IPCC).

Links to some popular media articles:

• The Washington Post — The world has just over a decade to get climate change under control, U.N. scientists say
• National Geographic — Climate change impacts worse than expected, global report warns
• The New York Times — Factbox: U.N. report on keeping global warming down to 1.5 degrees Celsius
• The New York Times — Why half a degree of global warming is a big deal
• CNN — Planet has only until 2030 to stem catastrophic climate change, experts warn
• New York Post (later republished by Fox News) — Terrifying climate change warning: 12 years until we’re doomed
• Popular Science — What you should know about the new climate change report
• Motherboard — We’re ‘nowhere near on track’ to meeting our climate change goals, UN report says
• The Economist — Why the IPCC’s report on global warming matters

I’ve spent some time reading the report, which is publicly available here, and this post is to share some of the key takeaways using 4 of the key IPCC graphs.

Though the articles above are largely factually correct, I disagree with the tone of some of them. In particular, I hate the title, “Terrifying climate change warning: 12 years until we’re doomed.” Believing we’re “doomed” is just as paralyzing and irresponsible as denying climate change. It has the effect of externalizing the problem, making it seem like an act of nature or something that’s being done to us. In fact, we are only “doomed” to the extent that we allow ourselves to be.

And, let’s be very clear: insofar as “doomed” means “dispossessed of homes, livelihoods, liberty, and cultural identity by the effects of climate change,” people (including Americans) are already being doomed this very moment. Just read my posts on Shishmaref, Kiribati, Fiji, or indeed Miami. Or, watch the news about the latest hurricane landfall and imagine a future in which those hurricanes intensify decade upon decade. Or take a trip to the Western U.S. during the summer. Or, read about the African “Road of Fire” populated by migrant people fleeing drought, water shortage, crop failures, and resulting violence in their former homes.

The point of the IPCC reports is to rationally describe the challenge and to forecast risks as a result of various policies we might pursue, over which we have control, with the ultimate purpose of defining policies to limit the damage and reduce the future risks.

So, to the IPCC Special Report on Global Warming of 1.5°C:

Who wrote it. There is evidently some question about this among some folks.

“It was given to me. It was given to me, and I want to look at who drew, you know, which group drew it. Because I can give you reports that are fabulous, and I can give you reports that aren’t so good.”

–President of the United States, Donald Trump, approximately 48 hours after the widely expected release of the report commissioned by the 195 nations that are signatories of the Paris Agreement. It’s now 30 days after the report’s release, and I cannot find any evidence the President ever found out “who drew” it, or ever returned to a bouquet of microphones to let us know whether it is “fabulous” or not so good.

It’s actually not a “drawing” per se, but it does contain many informative graphical renderings, two of which we will look at in this post.

In less than 10 minutes of dedicated Googling, I was able to ascertain with a great deal of clarity “who drew” the IPCC Special Report. The report was written by 91 scientists and government agents. Of those lead authors, the greatest number (7) were Americans; the other 84 were from 43 other countries. The lead authors synthesized contributions from 133 contributing authors who drew scientific data and conclusions from over 6,000 cited references in the scientific literature, primarily peer reviewed scientific studies. Drafts of the report were reviewed by some 2,000 registered expert reviewers from 124 countries who generated 42,001 expert review comments that were considered during production of the final report.

To be absolutely clear, there is no “opposing scientific view” on climate change with anything even minutely approaching the credibility of the above detailed effort. The IPCC reports represent, quite literally, the best human understanding of climate change, its predicted consequences, and possibilities for its mitigation.

Why they wrote it. At the time the Paris Agreement was adopted in December, 2015, the 195 nations signing the agreement committed to “holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels.” The latter goal was advocated for by the Pacific island nations, which stand to lose the most (which is to say, everything) from even mild levels of global warming compared with our current state. In response to that advocacy, the IPCC was invited to publish, in 2018, a special report on the distinction in global risks between 1.5°C and 2°C of warming, as well as global emission pathways required to achieve one outcome vs. the other. Basically, to answer the question, “Is going through heroics to achieve 1.5°C of warming worth it compared to 2°C of warming? And, if so, is it possible?” This is that report.

What it says, in a nutshell. The report is detailed. It’s 5 chapters and hundreds of pages long. Its key conclusions are very succinctly summarized in a 3-page list of Headline Statements and a 33-page Summary for Policymakers. I highly recommend reading them both. If you’re American, read them before you vote on Nov. 6.

But this is also a case where a picture is worth thousands of words, and so I’d like to reproduce here a couple of the figures the scientists “drew.” If you take nothing else away from the Special Report, sit for a moment with these two images.

First, this one:

The top panel is a graph of global average temperature increase (above the pre-industrial average) vs. year. The grey, squiggly line up to 2017 is the historical measurements (the same data I discuss in detail here). It’s squiggly due to natural variations, which create statistical uncertainty represented by the orange band around the historical data. The orange dashed line is the average projected temperature going forward at the current rate of emissions and global warming, and the horizontal orange error bar represents the statistical uncertainty in the time at which warming will reach 1.5°C. So, we can expect to reach 1.5°C of warming around 2040, but anywhere between 2032 and 2050 accounting for uncertainty. (How old will you be? How about your kids? Your grandkids?)

The purple, grey, and bluish plumes to the right of the top panel are projected global temperature rises based on 3 emission scenarios illustrated in the bottom 3 panels of the figure. The leftmost panel (b) shows annual net CO₂ emissions (amount of CO₂ emitted by fossil fuel use minus amount of CO₂ removed by tree growth, etc.), while the center panel (c) shows net cumulative CO₂ emissions. The rightmost panel (c) shows cumulative “non-CO₂ radiative forcing,” a fancy set of words for emissions of greenhouse gases other than CO₂, such as methane. Starting with the “middle” grey plume of future temperatures, that’s what is expected if we follow the grey emission trajectories in the bottom panels: reduce our global net CO₂ emissions to zero by 2055, in addition to a healthy reduction in other greenhouse gas emissions. If we accomplish the first part, but don’t reduce other greenhouse gas emissions, we get the purple projection. If we are more aggressive, reducing CO₂ emissions to net zero by 2040, as well as accomplishing a healthy reduction in other greenhouse gases, we can achieve the bluish projection.

Thus, it remains possible to ensure we limit warming to 2°C, and it’s even still possible to limit warming to 1.5°C, but either scenario will require dramatic changes in our energy economy over the next 20-35 years.

Here’s a second key graph in the new IPCC report:

These are bars that show scientists’ best consensus forecasts of the severity of impacts and extent of risks in each of a number of categories as a result of allowing the planet to warm various levels above pre-industrial temperatures. The grey band indicates our current level of warming. The risks and impacts get worse as the planet gets warmer (white = “no problem,” purple = “big and irreversible problems”). Anticipating skepticism and in acknowledgement that forecasts are uncertain, the risk colors in the various categories are labeled to indicate their levels of certainty based on available data (M = “medium,” H = “high,” VH = “very high”).

“Even the scientists were surprised to see … how much they could really differentiate and how great are the benefits of limiting global warming at 1.5 compared to 2 [degrees Celsius].”

–Dr. Thelma Krug, IPCC Vice-Chair, in a statement to Reuters

You can easily see in these simple bars the reasoning behind a goal of limiting warming to at most 2°C, or better yet 1.5°C — that’s the range over which key risks and impacts of interest to us (“heat-related morbidity and mortality,” anyone?) are going from “detectable” to “severe and widespread.” Risks in many of these categories are specifically spelled out in simple language in the 3-page Headline Statements, a quick and informative read.

In looking at the graphs above, it’s important to remember the specificity of the question being answered in this latest Special Report. Don’t interpret the “worst” purple plume in the top graph to be “the worst case scenario.” Any of the projections in the above graphs are actually quite good scenarios, which will result from an impressive feat of social and technological success — transforming our economy to reach zero net carbon emissions by mid-century. When we have done that, we will have good reason to be proud!

For a “worst case,” you need to look at similar graphs published in the last full report of the IPCC, the IPCC Fifth Assessment Report (2014):

The above pair of graphs show, on top, annual carbon emissions historically (black) and into the future (various scenarios). The grey scenario is “business as usual,” in which we refuse to admit the problem and just keep on as we have been. The blue scenario is one similar to those considered in the new Special Report: reduction to zero net carbon emissions around mid-century. The bottom graph shows how much warming we expect for each of the given scenarios, which is just a simple result of how much total CO₂ we’ve put into the atmosphere. “Business as usual” — climate change is a “Chinese hoax” and all that — is expected to get us around 4-5°C of warming.

Now, in the graph below, are the same risk bars applied to the broader range of temperature rise we might experience based on our choices starting right now. Lots of reds and purples associated with 4-5°C!

“This report gives policymakers and practitioners the information they need to make decisions that tackle climate change while considering local context and people’s needs. The next few years are probably the most important in our history.”

–Dr. Debra Roberts, Co-Chair of IPCC Working Group II assessing the vulnerability of socio-economic and natural systems to climate change, negative and positive consequences of climate change, and options for adapting to it

Use your zip code to check this handy voting guide and see how your candidates stand on the climate!

 

I am a scientist. For me, most decisions about things involve a hypothesis and supporting evidence. I have had a particular political hypothesis for some time. Today, that hypothesis appears supported by evidence.

Political Hypothesis: The super rich guys who say climate change isn’t happening, or we shouldn’t be worried about climate change, or we can simply ADAPT to climate change, will vanish when the sh*t hits the fan.

Consider the following tweets from President Trump over the past few days:

Texas & Florida are doing great but Puerto Rico, which was already suffering from broken infrastructure & massive debt, is in deep trouble..

— Donald J. Trump (@realDonaldTrump) September 26, 2017

…It's old electrical grid, which was in terrible shape, was devastated. Much of the Island was destroyed, with billions of dollars….

— Donald J. Trump (@realDonaldTrump) September 26, 2017

…owed to Wall Street and the banks which, sadly, must be dealt with. Food, water and medical are top priorities – and doing well. #FEMA

— Donald J. Trump (@realDonaldTrump) September 26, 2017

…The fact is that Puerto Rico has been destroyed by two hurricanes. Big decisions will have to be made as to the cost of its rebuilding!

— Donald J. Trump (@realDonaldTrump) September 29, 2017

“Ultimately, the government of Puerto Rico will have to work with us to determine how this massive rebuilding effort…will be funded.”  [The effort] “will end up being one of the biggest ever” [and Puerto Rico already has] “a tremendous amount of debt.” -President Trump, in a press conference on Friday.

The message? You’re already in debt and it’s super costly to rebuild your stuff.  You’re on your own.

This is a message that the town of Shishmaref, AK, I suspect, has already received loud and clear.

I am working on a draft article on the link between climate change and hurricanes Harvey, Irma, and Maria. Please look for it soon, but it takes some time. (Real research takes longer than impulsive tweets!) Suffice it to say, every expectation is that warmer oceans and atmosphere will bring us increasingly strong hurricanes (see evidence in my upcoming post!)

Please pay attention to that evidence, and consider where you, personally, come down on it. Because, …

When our leaders say, “don’t worry about climate change,” they are saying it with the exact attitude and intentions as the guy who encouraged you to steal the farmer’s apples, then took off when the farmer appeared with his shotgun.  The same as the guy who encouraged you to drink while under-age, then ran off and left you with the keg when the cops rolled up. They are having their fun, lying to you while their rich fossil fuel executive buddies get richer off fossil fuel technologies that, if rationality governed, should be going the way of rotary dial phones right now. But they have NO INTENTION of taking responsibility for the predicted consequences of climate change.

That will be up to you.

#rescuethatfrog