climate change

What Can I Do? Being a Climate Scientist Post-2016 Election

I felt gobsmacked on Tuesday night. I spent the day cooking for friends, excited to celebrate our first female president. As the results started to roll in, we ate carnitas and drank beer and mostly ignored the TV, confident in America's choice. Then North Carolina and Florida started to look more red than blue. We got quieter, and checked results on our phones, until one friend looked up and said “All the swing states are going for Trump.” Those swing states included Wisconsin and Michigan, states that I never thought of being up for grabs.

I moved to Minnesota this summer, and spent four months driving around the rural Upper Midwest, sampling lakes. There were a lot of Trump/Pence signs, and a lot of people that we talked to who probably voted for them. We chatted about water quality and the weird weather as we launched boats and explained our research. People care deeply about their lakes, in Minnesota, Wisconsin, and Michigan. Especially in rural Minnesota, everyone wanted to know about their lake health and talked about zebra mussels and marveled that we could measure algae blooms from space. I often brought up climate change, and not a single person tried to contradict me or pick a fight. I don’t know if they accepted the science of climate change, or if this was a symptom of the “Minnesota Nice” I’ve heard so much about. If they did accept climate change as real, I don’t think it swayed any votes in the rural Midwest.  I don’t think love for their lakes and forests was on anyone’s mind as they cast a ballot.  In retrospect, I wish I had tried to make that connection.

There are a lot of proximate reasons that liberals and progressives and marginalized groups are up in arms about a Trump presidency, paired with a Republican Senate and House.  There are immediate threats, easily linked to specific policies. But climate change – and many environmental issues – are background issues. Rolling back regulations on carbon emissions affects quality of life indirectly, but that effect is unequivocal. The disconnect, though, remains a key part of why communicating the threat of climate change has been so difficult. Each extra ton of carbon dioxide emitted means more sea level rise, more permafrost thaw, a greater threat to biodiversity and the services ecosystems provide. So, what can I, as a scientist studying these issues, do? What can you do?

I don’t know all the answers to that. It will be different for each person. But here are some things I will be doing and thinking about over the coming months and years.

As an educator, I will talk about climate change in every class I teach. I will talk about why climate effects how we live and the places we value.  Because, as others have said, providing students the tools to speak and act with authority will be even more important under an anti-science administration.  We will all have to be more resolute to protect our oceans and lakes, rivers and forests.  I will do my best to do this myself, and help students prepare for this struggle.

As a researcher, I will continue to explore the ways human action has influenced our aquatic systems, through climate and land use change. I will work to understand how rivers in the Arctic, lakes in the Midwest, estuaries in Texas are changed by our way of life and how those changes will feedback into the climate system and downstream ecosystems.

As an academic, I will work to make my institutions safe and welcoming for women, people of color, immigrants, LGBTQgroups, and disabled people. I will contact our Diversity and Inclusion office, and advocate to create opportunities for students from marginalized communities.  I will continue to be involved in the Earth Science Women’s Network, and Association of Polar Early Career Scientists, to make all of STEM more accessible, and to work in partnership with indigenous communities who are threatened by climate change.

As a citizen, I will write letters to my legislative representatives and city council and governor’s office, and yes, even the Trump transition team. I will do my best to articulate why climate change is not a partisan issue, why it will affect everyone who wants to vacation in Florida, or escape to a quiet lake, or just spend less money pumping water out of New York’s subway system.

As a new Minnesotan, I will seek out opportunities to educate the public and K-12 students about climate change and watershed management. Admittedly, this is the most nebulous of my plans. I do not have a network, yet, of local organizations and educators who could help enable connections with non-university students. I did in Texas, though, and this is something I will try to work on in the coming months. Ultimately, this might be one of the most important things that I, or any scientist, can do. There are a lot of people who love their environment – from fishermen in Texas to hunters in New England to everyone in Minnesota with a family cabin on a lake. I hope I can help them see that their voice and votes are important. That climate change will affect them and the places they hold dear, and no matter their political persuasion, they can help enact smart climate policy.

As an individual, I will find climate action organizations that I believe in and contribute either time or money to them. Again, this is something I need to research more. But there are a lot of people out there trying to advocate for climate change prevention and better energy policy. One of them (at least) will be a good fit for me.

Finally, I will do what I always do – I will read, and try to educate myself about climate change and diversity and improving STEM. I will say yes more often. I will try to be a better person and a fiercer advocate for what I believe in.  This year has left me feeling raw and drained, but I will try to work hard and be empathetic.

I’ll be honest. This will be a difficult, uphill battle. Optimism feels out of reach. Science, specifically climate change initiatives, has been on the chopping block for a long time. The House Science Committee has been on a vendetta for years now, and some scientists and environmental groups have been targeted by state government with Freedom of Information Act requests or frivolous investigations.  I think that will get worse. A friend, from Colombia, started asking me in a panic what we could do to stop the EPA from being gutted. She was galvanized because this matters not just to the US, but on a global scale. When scientists are ignored or intimidated into silence, it is difficult to know how we can accomplish anything. I don’t know that we can. But I think it will feel worse to not try.

So, that’s what I’m doing. Some of it is a continuation of what I have already done, some of it is new, some of it is stepping up my previous efforts. I hope you’ll consider what you can do.

Take a deep breath. Remind yourself of the places and people you're fighting for. And do what you can.

Take a deep breath. Remind yourself of the places and people you're fighting for. And do what you can.

Pleistocene Park

Wandering through taiga, tromping through thick underbrush of willow and birch in Siberia, it is easy to imagine yourself transported back to the last ice age.  Bison could be browsing over the next hill; cave lions napping across the river.  The Arctic feels wild and untamed, even though humans have left indelible marks on the landscape. 

Northeast Siberia is a historically important place - infamous during the Soviet Era, home to gold-mining industries and gulags.  Scientists now study the Kolyma because of a much more distant past, however.  During the Pleistocene, too little snow fell in the region to accumulate ice sheets.  The Kolyma remained largely unglaciated, unlike much of North America and northern Eurasia.  Instead, windblown dust deposits accumulated, burying the steppe-tundra ecosystem, and then freezing to form permafrost.  Slowly, these deposits, called yedoma, built layers of organic rich permafrost tens or even hundreds of meters thick.   They are still there today, storing carbon from 15,000 years ago and more.  However, yedoma no longer accumulates.  The ecosystem has changed drastically, from grassland to boreal forest.  A clue as to why can be found along the eroding Kolyma river bank at Duvannyi Yar.

At Duvannyi Yar, scientists have studied the exposed and thawing permafrost.  They’ve found ancient seeds, 30,000 years old, and germinated them in the lab.  And anyone can walk along the shore and find bones exposed by slumping permafrost as it degrades and falls into the river.  These bones reveal the rich ecosystem that thrived here during the Pleistocene, home to bison and musk ox.  Horses and reindeer.  Wolves and moose.  And, of course, mammoth.

Duvannyi Yar - an eroding river bank along the Kolyma where yedoma exposes ancient bones.

Duvannyi Yar - an eroding river bank along the Kolyma where yedoma exposes ancient bones.

These megafauna roamed the landscape, grazing and fertilizing grasslands.  Their high densities prevented trees from encroaching on the steppe tundra from the south by trampling any seedlings.  Much as the many grazers of the African savannah maintain that tropical ecosystem, their high-latitude counterparts performed the same function.  

Then, humans migrated north and east, eventually reaching the far corners of Eurasia.  With them, they brought a wave of localized extinctions (and some not so localized).  The great herds of bison and mammoth and horses disappeared from the Kolyma.  And with them, the steppe-tundra ecosystem. A recent paper in PNAS describes this process, globally.  The dense, diverse populations of large herbivores from yesteryear were fundamental to maintaining open woodlands and grasslands.  Remove those species, and the entire landscapes becomes more forested.

However, a few Russian scientists are trying to recreate the steppe-tundra, at a place called Pleistocene Park.   They have built fences to hem in their herds.  They traveled to the Wrangell Islands for musk ox and western Russia for bison and wapiti (a type of deer).  They lured horse herds with salt licks and captured baby moose to release into the park. 

And, of course, they have a Soviet-era transporter to knock down trees, in lieu of a mammoth.

It’s all very well to try to re-establish a lost ecosystem, but why?  Sure, there is inherent value in “re-wilding”, but there are also more practical reasons.  Namely, the steppe-tundra was much better at storing carbon in the ground than the current larch forests of the Kolyma.  Forests and mossy tundra that now dominate much of northeastern Siberia insulate the ground.  Snow accumulates more easily, and the bitter cold air temperatures do not penetrate as deeply into the permafrost.  The permafrost underneath taiga or moist, mossy tundra, while still frozen, is less cold than might have been the case in a steppe-tundra ecosystem.  Thus, the permafrost – and the millions of tons of carbon stored within it – can thaw more easily in today’s modern ecosystem than might have been the case if mammoth still walked.

Baby moose at Pleistocene Park

Baby moose at Pleistocene Park

Pleistocene Park and its founder, Sergei Zimov, been featured in a number of recent articles and papers about global extinctions of ice age megafauna.  I’ve enjoyed reading journalists’ descriptions of the places I’ve been, and the people we work with, but I think my favorite discussion of Pleistocene Park was in a recent book.  Beth Shapiro’s How to Clone a Mammoth discusses the science and ethics of “de-extinction”.  We might – emphasis on might – be able to raise some sort of mammoth from the grave, but what happens then?  Will it survive?  Should it survive?  Pleistocene Park is an obvious place where new mammoths might be kept, but that doesn’t mean de-extinction is advisable.  Still, I was delighted to scratch the ears of a baby moose while there.  I can only imagine what it would have been like to, instead, give a baby mammoth a pat on the head.

The Permafrost Climate Feedback

A synthesis paper of the Permafrost Climate Feedback just came out in Nature this week (paywalled, but it’s here).  Field buddy Jorien is a co-author, so congrats to her!  I’m going to take this opportunity, then, to wax eloquent about permafrost and climate.  Plus the paper has some cool figures that I think everyone should see.

Permafrost is any ground that is below freezing (0°C) for two or more years.  Permafrost can be icy – some yedoma soils contain up to 80% ice – but often it is just cold.  The easiest way to piss off an Arctic scientist – say permafrost is melting.  Permafrost thaws, it doesn’t melt (see the update at the bottom of the article.  We get testy). 

Permafrost soil carbon, from Schuur et al 2015.  Permafrost covers about 25% of the northern hemisphere land surface.

Permafrost soil carbon, from Schuur et al 2015.  Permafrost covers about 25% of the northern hemisphere land surface.

Often, permafrost has been frozen not just for two years, but for thousands or tens of thousands of years.  Some permafrost has survived as much as 740,000 years.  It acts like a giant freezer, storing animal bones and mammoth mummies.  But, even more importantly, permafrost regions store as much as 1670 billion tons of organic carbon.  To put this in perspective, that is more than twice as much carbon currently in the atmosphere or in terrestrial vegetation.  That carbon has been locked away for millennia, but the freezer is beginning to thaw.  As permafrost warms, the preserved soil carbon can be decomposed, releasing carbon dioxide and methane – both powerful greenhouse gases.

We, as a scientific community, have been trying to quantify this process.  How much carbon, exactly, is stored in permafrost?  What portion of the frozen organic carbon can be decomposed into greenhouse gases? How much of the permafrost will actually thaw over the next century?  What timescale will this process occur over – abruptly or over decades?  Where will the carbon decompose – in the soils, or in streams, lakes, rivers or estuaries?  We still don’t know all of this, but we have some pretty good estimates.

First, as you might have guessed, we are becoming more confident about how much carbon is actually in the permafrost soils.  Some of the more remote areas in Siberia and the High Canadian Arctic still need more measurements, but the Permafrost Carbon Network database now contains many soil cores from all over the Arctic, including deeper soil samples that used to be rarely collected.   Subsea permafrost is the biggest unknown.  This is permafrost that formed during the last ice age, when sea levels were much lower, and has since been inundated by rising oceans.  Still, estimates for permafrost carbon are converging around 1300 – 1700 Pg C (units are petagrams, or billions of tons). 

If permafrost does thaw, what percentage of the carbon contained can actually be mineralized, turned into CO2 or CH4?  This is a complicated question, and one of the most important ones.  Elberling et al. (2013, paywalled) did a great experiment where they incubated permafrost soil for 12 years to see how much carbon was lost.  Twelve years!  I was nine when they started that project (it also took them, like, 5 years to publish after completing the experiment because writing/publishing is ridiculous – another rant for another time). 

Anyway, as much as 75% of the carbon was mineralized – turned, by microbes, into CO2.  Not all soils are created equal, though.  A friend did some experiments in Cherskii, Siberia and only a small percentage of the carbon was lost.  Joanne was limited by her time in the field, so a longer incubation could have different results.  Other factors matter too – exposure to sunlight can break down organic molecules, releasing CO2 even faster.  The ratio of nitrogen to carbon (it’s juiciness, as one of my committee members would say) matters.  All in all, the decomposability or lability of organic carbon varies widely. 

Still, we can combine what we do know of the lability with warming projections, to try and estimate how much carbon will be released from permafrost over the next century.  These models still need work, but there seems to be some convergence between multiple methods.  Or, we’re not sure, but people using the different data and different methods seem to be coming to about the same answer, so let’s go with that for now.  Until we can get better data and better methods.

From Schuur et al 2015 again.  Different models predicting how much carbon will be released from permafrost by 2100, 2200, and 2300.  The dotted line is the average C released by 2100 for all models.

From Schuur et al 2015 again.  Different models predicting how much carbon will be released from permafrost by 2100, 2200, and 2300.  The dotted line is the average C released by 2100 for all models.

Including just gradual permafrost thaw (there’s also abrupt thaw, but I’ll save that for a different post), we seem to be facing 5 – 15 % of permafrost carbon loss during this century.  Again, putting this in perspective: land use change (deforestation, etc) released about 0.9 Pg C per year from 2003 to 2012 (as said in Schuur et al).  If that held constant over the century (unlikely, but just for arguments sake), that means human-driven land use change would emit about 90 Pg C by 2100.  Loosing 10% of permafrost carbon would be about 130-160 Pg over a century.

Of course, that is a VERY back of the envelope calculation, and permafrost carbon would only be a fraction of the fossil fuel emissions (9.9 Pg in 2013, and it increases every year unless policies change drastically soon).  Still, it is useful to think about just how important the permafrost climate feedback could be.  And none of the current climate projection models include the permafrost climate feedback – yet they all include land use change. 

What does this all mean?  The permafrost climate feedback will exacerbate climate change.  Warming climate thaws permafrost.  Permafrost releases additional greenhouse gases.  Greenhouse gases warm the atmosphere more.  More permafrost thaws.  This loop, or positive climate feedback, needs to be included in our decision making.  There are still unanswered questions about permafrost.  But we know that this carbon pool is vulnerable.  And we know that it will contribute to global climate change.

 

Ice wedges - the science of frozen cracks in the ground

There aren’t that many memorable papers.

I mean, there are thousands of decent or even good papers published every week.  But they all sort of blend together after a while.  I have a hard time keeping them straight sometimes.  Just today, I told my advisor the wrong thing about a paper I included in a literature review I’m writing.  It was not a good paper, and I had confused the methods from the not-so-great paper with those of a much better paper.  My point is that most papers are forgettable to an extent. 

Occasionally, however, you’ll read something that’s like a bolt through the sky.  You’ll sit up and say, “I want to do THAT.”  This week, that paper presented data from ice wedges in Siberia, then reconstructed winter temperatures.  Esoteric, yes.  But also really cool. 

Ice wedge formation

Ice wedge formation

First, what are ice wedges?  As much as a quarter of land in the northern hemisphere is underlain by permafrost, ground that is below freezing temperatures for two or more years in a row.  During winter, the extreme cold temperatures cause the ground itself to contract, forming fissures and cracks.  Once temperatures rise in spring, snowmelt fills those cracks.  The water re-freezes – after all, the soils around it are well below freezing!  Freezing actually causes water to expand, and the new ice wedge widens the gap slightly, and pushing surrounding frozen soils upwards.  Think a tube of toothpaste – you squeeze the sides together, and the toothpaste comes out the top.  The following winter, the permafrost contracts again, opening a crack in the ice and starting the process over again. See the little diagram I made to get a better idea.

These can get massive, and very, very old.  Meyer et al. (2015) just published a paper taking advantage of the age and sequential way ice wedges are formed.  They went to the Lena River delta (right), one of the largest deltas in the world.  Permafrost abounds, and previous work established the age of different parts of the delta fairly well.  Ice wedges are also common.

Figure S2 from Meyer et al. (2015).

Figure S2 from Meyer et al. (2015).

So, Meyer et al. went out a few times, to quote the study, “ice wedges have been sampled by chain saw.”

Yeah, science!  And chain saws.  When we sampled ice wedges on the Kolyma River, we used an axe.

Anyway, they cut out sections of the wedges, melted them and preserved the water.  Later, they ran isotopic analyses which told them a) the approximate age of the water using radiocarbon and b) the relative temperature using oxygen isotopes.  I’ll spare you the details of how the isotopes work – don’t worry, I’ll go into excruciating detail on that some other time.  For now, just know that higher oxygen isotopes mean warmer temperatures.  Using this, Meyer and his colleagues re-constructed 8,000 years of winter-spring temperatures. 

The winter-spring temperature reconstructions are almost unique in high-latitudes.  Most of our long-term temperature proxies – tree rings, for instance – are based on annual growing seasons.  Great, we need to know this.  But much of the recent anthropogenic climate warming in the Arctic has been during winter and spring.  We need to know – is this different than in previous natural climate changes?  What impact will winter warming have on carbon sequestration in permafrost?  How will winter warming impact hydrology, weather, the length of the growing season?  These reconstructions are a first stab at answering those types of questions.

The reconstructed climate from ice wedges reveals winter warming, opposite of other summer-biased climate records.  Again, I won’t delve too deeply into these mechanisms right now, but this was likely driven by changes in orbital forcing.  The shape of Earth’s orbit changes through time, on cycles of ~20,000 – 100,000 years.  These changes impact how much energy we receive from the sun, and its distribution.  Meyer and colleagues used models of past climate to show that winter warming was likely driven by these changes in our orbit around the sun.  At the same time, there was a significant increase in carbon dioxide concentrations during the 8,000 year record.  Reconciling this increase in greenhouse gases with a cooling in summer temperatures is accomplished by including these warming winter temperatures.

Figure 1F from Meyer et al. 2015.  The take-away: winter temperatures have a long-term warming trend, that has jumped up dramatically in the past 50 - 100 years.

Figure 1F from Meyer et al. 2015.  The take-away: winter temperatures have a long-term warming trend, that has jumped up dramatically in the past 50 - 100 years.

Alaskan ice wedges received similar analyses a couple years ago, but we have much less data of any sort from Russia compared to the North American Arctic.  I originally got involved in Arctic research as an undergraduate on a project aiming to correct this.  We went to the Kolyma River in northeast Siberia, and conducted all sorts of research on carbon cycling (see www.thepolarisproject.org).  I returned in 2013, and would love to go back again.  I work mostly on modern carbon cycling, these days.  But I’ve always found paleoclimate fascinating – reading about ancient climate and cultures launched me towards my present career when I was a sophomore in high school.  I want to do paleoclimate, and I want to get back to northeast Siberia.

The Kolyma River is home to a great science station, lots of good researchers spend their summers there.  And guess what else it has?

Ice wedges.

 

 

 

 

Meyer et al., 2015.  Long-term winter warming trend in the Siberian Arctic during the mid –to-late Holocene.  Nature Geoscience, 8, 122-125.  doi:10.1038/ngeo2349

"That's too many syllables!"

I can’t remember who told me this, but it’s emblematic of the responses I get when I tell people I’m a biogeochemist.  So, what do I actually do?  What is biogeochemistry?

The Global Carbon Cycle, from the IPCC 2013 Working Group I ( http://www.climatechange2013.org/ )

The Global Carbon Cycle, from the IPCC 2013 Working Group I (http://www.climatechange2013.org/)

Biogeochemists study how elements cycle through different parts of the Earth system.  Carbon, nitrogen, oxygen, and many other elements are essential for life.  Of course, they aren’t just important because of how they’re used by life forms, but also what role they might play in the physical-chemical environment.  Carbon, for instance, can be energy for organisms as part of a sugar molecule; a greenhouse gas when in the atmosphere as carbon dioxide; it influences the acidity of waters when dissolved at bicarbonate; or might be stored away for eons as calcium carbonate in limestone rocks.  We study how that one element moves through different systems, and interacts with the biology, chemistry and physics of its environment.  We do the same for other elements – nitrogen, calcium, oxygen, iron, and plenty of others.

As you might guess from my example, I mostly am interested in carbon.  It’s in the food we eat, and the air we breathe.  It’s in our water, it’s the energy source for most of our electricity, and the structure for many of the rocks we stand on.  It’s important.

Humans are also changing where carbon is found.  Hundreds of millions of years ago, during the Carboniferous Period (get it?), wetlands and lowland swamp forests covered vast regions of the continents.  Temperatures were warm, oxygen was high, and life was big: this was the age of giant dragonflies and towering tree ferns.  The carbon that formed the tree ferns and other plants in these swamps was eventually buried and preserved in sediments.  Add time, heat, and pressure – the result is coal.  Coal is largely 300 million year old dead plants.

And, as you know, we’re burning that coal.  Other fossil fuels – methane/natural gas and oil – have similar histories.  Stored away for millions and millions of year, now combusted and turned into CO2. 

For now, I won’t get into the science of climate change beyond this: it’s real.  It’s not a hoax.  And humans are driving it.

The really interesting bit, to me, is that these fossil fuels are not the only potential sources of carbon to the atmosphere.  Look at the tropics – how much carbon do you think is stored in the Amazon forests?  And how much of that is released when you slash-and-burn it, or during a drought?  How much carbon do you think is released when the Indonesian rainforests are replaced by palm oil plantations?  Hint: it’s a lot.

Yedoma soils in NE Siberia, with ~30,000 year old plant roots exposed.  Photo courtesy of Chris Linder.

Yedoma soils in NE Siberia, with ~30,000 year old plant roots exposed.  Photo courtesy of Chris Linder.

Or, go to the poles.  Look at the soils.  That soil has been frozen for thousands, tens of thousands of years.  Since the last ice age, in some cases.  Some places, you can look at the soil and see roots and plants that have been preserved for 30,000 years.  Many of those soils are peats, sphagnum moss piling on top of each other and compressing and degrading for thousands of years.  Maybe you’ve heard of how in Ireland or Scotland, people would burn peat to heat their homes when firewood or coal was scarce.  It’s the same idea – compress peat for a few million years, and you’d end up with something very like coal.  In fact, the UN classifies peat as a fossil fuel.

Frozen northern soils – permafrost – hold about twice as much carbon as is currently in the atmosphere.  Thaw those soils, free them up so that the plants and moss and roots and all the little bits of organic matter can start to rot, and what starts to happen?  Where does all that carbon go?

That’s what I want to know.

And I’ll let you know how I’m trying to answer part of that next time!