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Best of Reddit AMA series with ASU's Greg Asner

Asner lent his expertise in ecology, remote sensing and climate change during an all-day Ask Me Anything session


Greg Asner, the director of the Arizona State University Center for Global Discovery and Conservation Science

April 28, 2020

Greg Asner, the director of the Arizona State University Center for Global Discovery and Conservation Science, recently lent his expertise in ecology, remote sensing and climate change to Reddit’s community during an Ask Me Anything (AMA)

We’ve compiled the best questions and answers from Asner’s AMA here. 

Question: What changes have you observed, or what do you expect to observe, in relation to climate change from COVID-19? 

Answer: With Earth Day yesterday, and this week in general, this has been the No. 1 question posed to me. Greenhouse emissions are down for now — and that's good for ecosystems and human health — but we don't know if or how that will last, or likely not, when the pandemic eases up. The same goes for wildlife trafficking. 

The question is: Will we learn and collectively drive ourselves to take a new path to lower emissions and less ecosystem destruction — or not? This isn't an over-the-horizon set of issues finally made obvious by the first modern-era pandemic. Science has known this — but now we all know it — so we need to work together to act. I'm feeling positive because lowering emissions and reducing ecosystem destruction is not that different from mitigating the spread of a virus; it has to be done through cooperation from community to international levels. COVID-19 is giving the world a practice run at solving issues that underly the disease.

Q: What are your long-range predictions?

A: We need to work globally to generate a set of actions that will reduce climate change, reduce deforestation/wildlife trafficking and improve economic security for more people. The pandemic is an accelerant in the call to move on these basic principles, no matter how hard it may be to do so. In 10 years’ time, I honestly think we will have taken some critical turns towards these goals, and if not — well, I know from a biological standpoint that we can't just keep pushing the challenge to the next generation.

Q: From the outside, you seem to have pivoted from the terrestrial to the marine domain almost seamlessly. Have you faced any big challenges in this respect? 

A: It will be surprising to learn that I started in the ocean. It's just that my first job gave me an opportunity in the terrestrial world, and so yup, it took me about 25 years to get back to the ocean! But two things opened up the possibility of adding marine applications (not replacing terrestrial — we are still 50% land-focused). The first is that these marine heat waves that cause coral bleaching fully grabbed my heart and soul — and not enough work has been done on these issues compared to land issues. The second is that our science and technology development for land applications had matured enough that I saw a pathway to coral reef applications. And also, I'm willing to take on more scientific risk at my age and stage. 

So here we are mapping forests, reefs and other ecosystems with ever-evolving approaches. I'm most excited by the amazing young scientists that are finding technical solutions to all of our (sometimes, my) somewhat outlandish science questions like, "Can we map coral species on the seafloor from an airplane?" As long as the physics and biology support the pathway, why not? Start with the physics and biology.

Q: What results of your research have surprised you the most? 

A: I work at a range of scales, from field-based operations (boots on the ground, fins on the feet) to airborne mapping and to satellite observations. When you combine all of this, you get something unique — a view of what has happened (or is happening) over huge areas — yet with high spatial or "biological" resolution. This is like "seeing the forest for the trees." 

I start with this because, by doing so, usually I get a shocking view of our impact. Examples range from the effects of militaries on ecosystems in the South China Sea to the impacts of thousands of gold miners in the Amazon Basin. At this point, however, after more than two decades of doing this work, my biggest "surprises" are not the negative stuff I see day-in and day-out, but rather the positive nuggets I find along the way. More than once, I have emerged from the field or from my mapping lab, jumping around excited to find a coral reef that miraculously survived a blistering ocean heat wave. My team and I have discovered previously unknown forests of species in the Amazon, despite deforestation and severe climate-induced drought. Some of these areas (but not enough) are now under increased protection. Will these and other nuggets of joy and hope persist and become the seeds of our future planet? I sure hope so, and that's why I've been expanding my personal role outside of the core science, to help people find the good to protect before its too late. 

Q: We're going through quite a boom in spaceborne sensors at the moment, but what are the next big things in remote sensing from your perspective?

A: Yes we are! I think the main frontier is that the technology (both hardware and AI) is breaking the old barrier trade-off between spatial resolution and temporal frequency of observation. Both are being simultaneously solved now. My lab routinely sees any part of Earth’s land mass and all coral reefs on a daily basis at 4-meter spatial resolution. It will only get better, and that opens huge possibilities. But as or more important, the frontier will include a breaking of the "spectral barrier." We are on the verge of being able to do all that I said above with much more spectral detail, far beyond the range of the naked eye or standard infrared. This world is way different from when I entered it in the ’90s!

I truly believe we have entered the age of Earth Management. Our collective impact is certainly global now, so that means we have to manage globally under various centralized (i.e. U.N.) and decentralized approaches (i.e. countries, subnational jurisdictions, communities). You can't do this without timely spatially-explicit ecologically and societally relevant information as the Earth system changes. To do that, you need remote sensing. I think various combinations of spatial, temporal and spectral (and active) remote sensing are not just continuing in need but are greatly growing in need.

Q: How do you manage to continue such necessary work and keep morale up in the face of continuous denial of science and missed opportunities by governments worldwide to try and slow climate change?

A: Great question. I remain inspired by the effort of so many people, from science to policy and everyone in between. Yes, humankind is losing more than winning on the climate front, but we have created organizations, knowledge capacity, science, technology and more to tackle these challenges. It's really up to the populace to demand — through voting and patterns of consumption (supply/demand) — change in our present course.

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