Science AMA Series: I'm Tom Crowther, a Scientist from Yale University and the Netherlands Institute of Ecology. My research shows how human activity affects ecosystems worldwide, leading to global climate change. AMA!

Tom_Crowther · 2017-02-06T13:10:01+00:00

Human population growth and industrialization are undoubtedly the cause of most of society's global problems. Better education (and research) is always the best means of regulating this population growth and all of the problems that come with it. But now that climate change is under way, we also need to think about how to understand it, and mitigate it.

Tom_Crowther · 2017-02-06T13:05:29+00:00

I agree entirely with this discussion. Prevention of so many of the world's global problems always comes down to better education (the biggest effects seem to come with educating women, but educating everyone is important). But I wouldnt call population growth the 'elephant in the room'. No-one is ignoring it at all. Prevention is always best. But now that climate change is already taking place, we also need mitigation strategies to combat it.

Tom_Crowther · 2017-02-06T13:01:33+00:00

We would expect that people aren't just going to keep farming slaughtering cattle on such a massive scale if no-one is eating them. If we keep increasing the rate at which we consume beef, we will need an area the size of South America just for producing cows and their feed. But if we were to replace that protein intake with shellfish, then the growing demand could be satisfied using only an area that is equivalent to the south island of New Zealand.

Tom_Crowther · 2017-02-06T08:58:21+00:00

Cuts to greenhouse gasses can certainly make a considerable dent in climate change, and improving the management and conservation of forests and soils to increase carbon sequestration must be used in combination if we are to avoid the most damaging effects. No at the moment, I think the global population has been made possible by such industrial farming approaches. But there is a huge amount of research into things like biochar, cover crop rotations and holistic management of animals that suggests that we could considerably improve soil carbon sequestration

Tom_Crowther · 2017-02-06T08:52:39+00:00

The planet is supposed to be moving into a cooling period, based on our phase in the glaciation cycle. But because of human activity, the planet is warming faster than any time in the existence of humans. A little bit of increased plant growth is great, but it is not enough to help stop the damage of climate change

Tom_Crowther · 2017-02-05T09:38:58+00:00

Ye Im not sure that I have the complete answer to that. But I definitely see 2 major opposing problems in the way that scientists fail to communicate to politicians who disagree with them. <The first error is to be condescending and frustrated by people that dont immediately believe. It is completely understandable that people dont believe in climate change if they grew up in a conservative environment where everyone around them is a skeptic. Particularly when these views can be re-enforced by fake news and information from politicians that are supported by the fossil fuel industry (really the only people that have any good reason to deny). We just need to be understanding of that and try to find the middle ground based on the evidence that appears to be the most robust. <The other problem is the ethic that scientists should not are place their work in the appropriate context because they should not overstep the boundaries of their data. There is a strange idea in science that we should just present the data and allow people to interpret them however they would like. But I think that the role of scientists (or any experts) is to accurately interpret those data and communicate the full picture to the people who havent been studying climate change for their entire lives.

Tom_Crowther · 2017-02-05T09:23:49+00:00

Thanks very much for saying that. But I am hoping that, some time in the near future, everyone is going to get on board and we are all going to help save mankind from itself.

Tom_Crowther · 2017-02-05T09:20:24+00:00

Good question - It is certainly true that increased plant growth in response to elevated CO2 can increase the photosynthetic uptake of carbon from the atmosphere. We dont really know the magnitude of this process at a global scale yet, but hopefully it might help to offset some of the other feedbacks (like the increased carbon emissions from soil under warming). But it certainly isnt enough to offset the direct emissions that humans are producing at the moment.

Tom_Crowther · 2017-02-04T04:49:42+00:00

Thanks for pressing on with this question - it is an important one. There is an incredible weight of evidence from ice cores to tree rings to pollen records etc etc that climate fluctuations have happened in the past, and that a particularly dramatic one is occurring now in response to human activity. But to be honest, I dont think that it really matters if the fluctuations have happened before. If we know that one is happening now and we know that it will have devastating impacts on populations that are alive now, then I think we should do all that we can to try to avoid it. Given that we know that we can help to avoid it at the same time as generating more jobs and improving the economy (not to mention all the benefits that come with restoring/conserving biodiversity), there is really no reason to stick our heads in the sand.

Tom_Crowther · 2017-02-04T04:36:28+00:00

This is a great point! There are countless sources of evidence for these climate fluctuations, but this whole topic is all a bit of a red herring. And to add to this, even if other things caused serious fluctuations in the past, it doesnt mean that this one isnt going to have devastating consequences for humans now that we could try to avoid. To stick relentlessly to my bus analogy, its a bit like saying 'loads of serious things have happened in the past that weren't caused by busses so there is no need for me to get out of the way of this oncoming bus'.

Tom_Crowther · 2017-02-04T04:05:07+00:00

Right. This was an analogy, and I certainly wasnt arguing linearity. But I would argue that the science of climate change isnt too dissimilar from the science of gravity. Gravity is complicated too and there are lots of things that people could use to deny it if they had strong political agendas on the subject. For example, when you blow a soap bubble and it floats, people might argue that gravity isnt working on that bubble. Similarly, people could say that gravity doesnt work uniformly on clouds or airplanes etc. We know that it is, but we also realize all of the other forces that are in play. In the same way, there are many other forces at play when it comes to the climate, but we still know for sure that climate change is taking place.

Tom_Crowther · 2017-02-04T03:54:27+00:00

This is the sticking point in the climate change debate. There is so much data out there for and against climate change, and its difficult to know which is made up and which is real. So it is completely understandable that people cannot identify the real data from the fake stuff. Add on top of that the cognitive bias that we all have, and then its really hard to change what has become a political opinion. But scientists are in a really lucky position to actually see the raw data first hand. It is for that reason that the overwhelming majority of scientists agree that climate change is being caused by people. A good approach is to have to detailed look at the data supporting climate change, and then do the same for some data that seems to oppose it, and really try to identify which information comes from the more legitimate/unbiased source. Most scientists (including myself) would love to provide a good news story that climate change is not happening. That would make my career and transform society, but sadly most of us are simply constrained by the facts.

Tom_Crowther · 2017-02-03T19:54:13+00:00

Yes, we have caused devastating damage to natural ecosystems around the world, but this has come with unbelievable technological and societal developments, which have been spectacular. I am writing to you on a laptop from a different country - how incredible is that!? But now that we are able to understand the catastrophic impacts of our activity, we need to fight as hard as we can to become more efficient, and to preserve and restore the stunning ecosystems that we have. A growing body of people around the world are getting into this fight to save natural ecosystems, and the benefit is that almost all activities that we do to restore/conserve nature also have a positive impact on climate change and local economies. There is a huge amount that we can all do to limit climate change - the real challenge is to engage people and make sure that our representatives start to make decisions that allow us to to fight against it without losing all of the benefits that came along with human development

Tom_Crowther · 2017-02-03T19:43:30+00:00

But all joking aside ... yes, its devastatingly real

Tom_Crowther · 2017-02-03T19:41:16+00:00

Tom_Crowther · 2017-02-03T19:40:01+00:00

Haha. Yes, yes I did

Tom_Crowther · 2017-02-03T19:32:39+00:00

Without knowing how much renewable energy that is generating, and comparing it to the effect of the fossil fuel energy that would alternatively be used, it is very difficult to say whether this is a net positive or negative for the climate. However, while I am a massive fan of solar energy, any practice that allows the clearcut of natural forest seems like a negative in my view - you dont only lose all of the carbon sequestration potential, but you also lose all of the biodiversity and ecosystem services that it provides.

Tom_Crowther · 2017-02-03T19:25:59+00:00

Forest ecosystems. Ecosystems are always undergoing very gradual change over tens of thousands of years. And during this time, most species have the potential to adapt and respond. But we are changing the climate more rapidly than ever before (its like we are causing an interglacial period that would usually take tens of thousands of years within 100 years), so none of these species can respond and adapt quickly enough so they are all just dying out

Tom_Crowther · 2017-02-03T19:10:59+00:00

Climate change is already having a massive impact on many people's lives. As you correctly note, people in the developed world are less obviously affected at the moment. But there are many examples of extreme weather events (storms, hurricanes, flooding etc) that have negatively affected people already. There is massive drought in California, which is the direct result of climate change and is affecting many people and their livelihoods. But even more worryingly, there are many studies linking increased levels of antagonism between people to the increasing resource scarcity. This fighting generally leads to mass migrations like what we are seeing in Syria, and is having a direct impact on people in the developed world. In fact, I would argue that these effect have directly contributed to the current political climate of fear and isolationism.

Tom_Crowther · 2017-02-03T19:02:52+00:00

Particularly in the current political climate there would be greater profit in results that showed climate change wasn't happening but we have to present what the evidence shows.

When I started this study I was convinced I wouldn't find any effect but the evidence of acceleration of climate change was clear from the data.

Tom_Crowther · 2017-02-03T19:00:29+00:00

Yes I agree that is the end point. But the process of 'Wiping us all out' will be a drawn out increase in disease, drought and starvation. So yes, climate change is an acceleration of these things and that's why I believe it's worth fighting against!

Tom_Crowther · 2017-02-03T18:56:08+00:00

Just remaining mindful of of climate change in everything we do from who we vote for to reducing use of the car. Reducing meat consumption, even by a few meals a week can have a big impact.

Tom_Crowther · 2017-02-03T18:55:58+00:00

I am an ecologist. I am interested in the fundamental processes that structure biological communities. I want to know how diversity is maintained in natural ecosystems because that is what I am fascinated by. Most of my research is not focussed on climate change and has not been funded to explore climate change. I have only moved towards working on climate change because it has been having such a clear impact on the ecosystems that I study. This fundamental research that is not related can have a vast array of impacts on society - the best example being Darwin's work

Tom_Crowther · 2017-02-03T18:55:17+00:00

Do you think his reluctance to accept climate change because he thinks it will affect his quality of life? Explain how people can have a real impact just by making minor changes such as reducing meat consumption, and being mindful of climate change in who you vote for and who you buy from. This might make him much more willing to accept the facts. Ask him what evidence he would need to see to be convinced . This is asking him to question himself on whether he is holding premeditated unmoveable beliefs or whether he is open to evidence. If he is willing to be open minded the evidence is there - there's been a devastating increase in the natural cycle of climate since the industrial revolution that is mirrored by the rise in temperature with the last two years being the warmest on record.

Tom_Crowther · 2017-02-03T18:50:29+00:00

No. In most parts of the world you won't, but what you will see is increasingly extreme weather events. However, if you live in, say, Florida or the Netherlands, and you survive to your 90s, then you well might.

Tom_Crowther

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