No 2109 Posted by fw, November 28, 2017
“You start to imagine how another degree Celsius with warming can have local impacts through much higher seas, more heatwaves, more heavy rain events. But the further we increase global average temperature again, the bigger the risk of climate surprises … but also systemic impacts, right? This is the idea that even if, say, a particular city tried to prepare itself for those heatwaves or flood events, the further the climate system gets pushed, the bigger the chance that that city, for example, will be impacted by climate changes in other places — maybe places where it’s harder to adapt. Maybe that’s the food security example I gave. Maybe it’s human conflict and migration due to climate change. Maybe it’s pest outbreaks, new diseases emerging. The further we increase warming, the bigger the chance of a whole bunch of surprises that are very hard to plan for.” —Dr. Radley Horton , The Real News Network
Dr. Radley Horton, a contributing author to the new report out of Washington, is a climate scientist at Columbia University. His research focuses on extreme weather events, the limitations of climate models, and adaptation to climate change.
On November 3rd, the Trump administration released a comprehensive climate report, Climate Science Special Report: Fourth National Climate Assessment, Volume 1. The report is mandated by Congress to inform the public and government about climate change. It’s an authoritative assessment of the science of climate change, with a focus on the United States. It represents the first of two volumes of the Fourth National Climate Assessment, mandated by the Global Change Research Act of 1990. It appears that the report was not censored despite fears earlier this year that the Trump administration might try to suppress its release. The report includes contributions from scientists both outside and inside government, including from NASA.
Critically, it contradicts not only President Trump’s stated view on climate change but also the predominant view in the Republican controlled Congress. The report affirms that not only is climate caused by human activity, but the climate crisis is getting worse and that we can resolve this crisis only by dramatically curbing our use of fossil fuels.
Below is a repost of Dimitri Lascaris’ interview of Dr. Horton on The Real News Network. My subheadings, text highlighting and some bulleted reformatting have been added. The embedded 16:37-minute video is included, along with my corrected version of TRNN’s error-filled transcript.
Alternatively, watch the video on TRNN’s website and access its transcript by clicking on the following linked title.
Contributing author to the report for the US Congress, Columbia University climate scientist, Dr. Radley Horton says more extreme weather events will be more common if U.S. doesn’t curb use of fossil fuel.
New Washington climate report contradicts Trump, affirms worsening climate crisis
Dimitri Lascaris — This is Dimitri Lascaris for The Real News reporting from Toronto, Canada. On November 3rd, the Trump administration released a comprehensive climate report. The report is mandated by Congress to inform the public and government about climate change. It appears that the report was not censored despite fears earlier this year that the Trump administration might try to suppress its release. The report includes contributions from scientists both outside and inside government, including from NASA. Critically, it contradicts not only President Trump’s stated view on climate change but also the predominant view in the Republican controlled Congress. The report affirms that not only is climate caused by human activity, but the climate crisis is getting worse and that we can resolve this crisis only by dramatically curbing our use of fossil fuels.
Dire predictions warn average global temperature could reach 5°C by 2100
The predictions in the report are dire. One of its key findings is that without major reductions in the greenhouse gas emissions, the increase in annual average global temperature relative to pre-industrial times could reach an astonishing nine degrees Fahrenheit or five degrees Celsius or even more by the end of this century. Today we are pleased to be joined by one of the contributing authors of the report, Dr. Radley Horton. Dr. Horton is a climate scientist at Columbia University. His research focuses on extreme weather events, the limitations of climate models and adaptation to climate change. He joins us today from New York City.
2017 is on track to be one of the hottest years on record
Before we talk about your report, Dr. Horton, I’d like to ask you about an important announcement made on Monday, November 6th, the opening day of the 23rd conference of the parties under the UN Framework Convention on Climate Change in Bonn, Germany. At the opening of COP23, the UN’s weather and climate agency reported that 2017, a year in which we have seen record breaking extreme weather, is on pace to be one of the three hottest years on record. Please talk about the significance of this particularly in a non-El Nino year.
Although a non-El Nino year, 2017 can still be near the top of the warmest year on record
Radley Horton — Yeah, I’m glad you brought this up because based on what we’ve seen from the first 10 months of the year, it is an extremely warm year, probably either the second or third warmest year on record. El Nino years, where we have these sort of unusual warming in the eastern Pacific and Central Pacific ocean, a phenomenon that happens naturally, independent from climate change, can be as much as half a degree warmer globally than your typical non-El Nino year. As you noted, 2016, which broke a record for warmest year, had been an El Nino year. We’re not getting El Nino this year, so we’re not going to be able to break that record but we’ve had a string 2014 through 2016, each of those years was the warmest on record. The fact that 2017 without the warming effect of El Nino can still be the second or third warmest year on record really is meaningful and part of a broader context.
Except for one year, every year since 2000 has been among the 17 warmest years on record
If we look globally at the years since 2000, every single one of those years has been among the 17 warmest years on record except for one year. 1998 made its way into that record, which was also a strong El Nino year. Basically we’ve reached a point where essentially more or less all of the last 17 years have been the warmest on record with this one exception of 1998.
Lascaris — To a layperson like myself, that sounds very much like a new normal. Is this what we can anticipate for years to come?
We are already experiencing more frequent extreme heat events, more heavy rain events and more frequent coastal flooding
Horton — The statistics have already shifted. Climate change isn’t just a problem of the future. A lot of our infrastructure, species were adapted for a climate of the past. It was a climate with variability but a lot of our decisions to move into coastal zones for example, the infrastructure we built was built for a statistical climate that no longer exists. We’re still going to get some cold years. We’re still going to get plenty of cold days but the overall statistics have already shifted so that we’re now seeing for example much more frequent extreme heat events than we did in the past, more heavy rain events and much more frequent coastal flooding.
Lascaris — Let’s talk about the report to Congress to which you contributed. Are the possible temperature increases predicted or envisioned within that report greater than the last set of estimates that the scientific community produced, and if so, to what degree? I mean, how much is our understanding of what we’re likely to experience worsened in the last few years?
What’s new in this latest report?
Horton — I think this report is very similar to the national climate assessments of the past. For example, the intergovernmental panel on climate change global reports that we’ve been seeing for the last 25 years. Which each of those assessments every four years or so, we do get new science.
Most of the findings are just incrementally advanced. Some things we already knew say five or 10 years or so ago. We already knew the climate was warming. We already knew humans were responsible. We already knew that we’re seeing more frequent heat, less extreme cold events.
There are some things in this new report where we really did push a little further than we have in the past given some of the latest science. I’ll tell you a little bit about some of the ways that we did push further in this latest report, given some of the emerging science.
As CO2 increases, we risk outcomes that even climate models can’t predict – such as impacts of melting Arctic ice
One of the things we really highlighted is that there’s a real chance of tipping points and surprises in the climate system. The further we push the climate by increasing greenhouse gasses due to human activities — carbon dioxide is already about 40% higher in the atmosphere than it was before the industrial revolution, before we started putting coal and fossil fuels into the atmosphere — and as we’ve turned up that dial on carbon dioxide, we’ve increased the risk of outcomes that climate models can’t even predict. Things like rapid melting of ice that’s on land that as it melts could increase sea level dramatically, could change the … will change the color of the surface of those Arctic sea ice for example. It was where in the past you had a white surface — ice that was very reflective of sunlight — as that ice starts to melt, we have a dark surface. The ocean that’s very effective at absorbing sunlight causing more warming, melting more ice. That’s an example of a positive feedback.
The concern is that climate models may underestimate the risk of some of these outcomes
We know that climate models to some extent can capture those kinds of positive feedbacks. We’re becoming more and more concerned that climate models may underestimate the risk of some of these outcomes. The further we push the climate system by emitting greenhouse gases, the greater the risk of those kind of tipping points that lead to more rapid changes.
There’s also a risk of multiple extreme events leading to larger impacts
We’re also seeing more and more evidence that there’s a risk of multiple extreme events leading to larger impacts than you get with one extreme event. For example, maybe the jet stream in the future — that high altitude current of air in the mid-latitudes — may change in ways that give us more simultaneous droughts and heatwaves and multiple, say, agricultural bread baskets around the world, increasing food security risks for example. That’s something that climate models, we think, can’t perfectly capture — they may underestimate the risk of changes like that.
Lascaris — One number that really stood out for me, based on the literature I’ve seen in the past, was my understanding that if we continue our current consumption levels of fossil fuels, current trends remained with a business as usual scenario, that we would see a global temperature increase in the range of three degrees Celsius above pre-industrial levels but this report talks about the possibility, not necessarily the probability, but the possibility of a temperature increase in the range of five degrees Celsius or more within this century. What would North America look like? What are the major impacts that we would see on North America in such a world?
A 5°C temperature increase is “extremely unlikely” but even 2°C can have “catastrophic impacts”
Horton — I think the first thing to highlight is that fortunately we think that five degrees Celsius with warming globally is extremely unlikely under any scenario. It’s important to highlight that but even two degrees Celsius can have catastrophic impacts on many parts of the world. Just to give a little example of it means, in parts of the US we’ve already seen roughly a foot of sea level rise over the past century. Some locations along the eastern US coast, places like Norfolk, Virginia are already seeing nuisance flooding events happening three or four times more often than they did say 40, 50 years ago.
Even with only about a 1°C temperature increase we’re getting record-breaking heat and cold events
We’re already seeing in the last 15 years over the US twice as many record-breaking extreme heat events as we’re getting record-breaking cold events. That’s all happened with just about one degree Celsius of warming with less than a foot of sea level rise in most places.
Imagine what impacts a 2°C warming could have
You start to imagine how another degree Celsius with warming can have local impacts through much higher seas, more heatwaves, more heavy rain events. But the further we increase global average temperature again, the bigger the risk of climate surprises like I described a little while ago, but also systemic impacts, right? This is the idea that even if say a particular city tried to prepare itself for those heatwaves or flood events, the further the climate system gets pushed, the bigger the chance that that city, for example, will be impacted by climate changes in other places — maybe places where it’s harder to adapt. Maybe that’s the food security example I gave. Maybe it’s human conflict and migration due to climate change. Maybe it’s pest outbreaks, new diseases emerging. The further we increase warming, the bigger the chance of a whole bunch of surprises that are very hard to plan for.
Lascaris — Now, in a recent Op Ed in the New York Times that you co-authored, it was entitled The Climate Risks We Face, you wrote about the possibility, perhaps it’s even a probability at this stage, of reaching a new benchmark of 410 parts per million of atmospheric CO2. You said this is an amount never before experienced in the history of our species. Based on current trends when do you expect we will reach that benchmark and given where we now are and where we’re heading and likely to head in terms of CO2 concentrations in the atmosphere, is there any longer a significant meaningful prospect of avoiding global warming in excess of 1.5 degrees Celsius?
Essentially, we’re already at 410 parts per million of atmospheric CO2
Horton — Yeah, those are, you’ve asked some really hard questions there. The first one’s fairly easy. In terms of 410 parts per million, I would say we’re effectively already there. There is some difference between crossing that threshold for a day, crossing that threshold for a month, versus crossing it and having it the average over the entire year, but really it’s just a matter of time — in the next few years we get to that 410 essentially forever. Forever at least in the time scale of human experience, unless we come up with some ways in the future to dramatically draw down carbon dioxide from the atmosphere, which we don’t have the capacity to do today. We’re already essentially at 410 I would say, in answer to that question, parts per million.
We’re almost at 1°C now and we are going to get to 1.5°C
The question about 1.5°C, a lot of the reports suggest that if global emissions of carbon dioxide just continue at their current level for say as little as 5 or 10 more years, the odds are we will cross that 1.5°C threshold because greenhouse gases last in the atmosphere for so long. We’ve already locked in additional warming beyond the 1°C that we’ve already had. We basically do have to plan for the world of 1.5°C warming. Realistically, there are some sectors such as aviation, where no alternatives really exist right now for the use of fossil fuels. I do think we’re going to get to 1.5°C. I also think it’s absolutely critical that there be a global effort to do everything we can to dramatically draw down emissions. That’s my personal perspective.
Lascaris — Let’s talk about an objective that hopefully is within the realm of realistic possibility remaining within a global temperature increase of 2°C. Broadly speaking, what do you think needs to be done in order for us to achieve that objective and within what time frame?
If global emissions remained flat, we’d have about 25 years to stay under 2°C
Horton — Yeah, so we think that if current emissions were to stay globally at the level they are today, we’d have roughly 25 years, roughly a generation, maybe a little less that we could emit at the current levels to stay under two degrees Celsius. At which point, we’d have to immediately go to zero emissions.
In order to stay under 2°C we need rapid efforts right away
In order to make that happen, we’d need rapid efforts right away. More specifically towards your question, I think a few things already happening that need to be accelerated. First, it’s important to note some sources of optimism:
Over time, I think those kind of initiatives could lead to a societal tipping point potentially where basically investors insist that companies plan for the climate of the future and therefore take steps to reduce their emissions.
Those are a few of the strategies at the global scale.
Lascaris — Just to clarify and in conclusion of what you just commented upon. When you said that we had approximately 25 years or one generation of current emissions, were you, did you mean by that that if emissions remained flat during that period, we had 25 years, or did you mean that we had 25 years if they continued to increase at expected trend in accordance with current expectations?
Horton — No, it’s really just about 25 years if they stay at the emissions levels of today. It’s not even planning for the growth in the future. That means we’d essentially have to go to zero the following year. That highlights the urgency of acting today. When we make an infrastructure decision like a coal plant for example, we’re essentially locking in decades of future emissions because the primary cost is upfront.
Lascaris — This has been Dimitri Lascaris speaking with Dr. Radley Horton, a climate scientist with Columbia University about a new congressionally mandated report on the climate crisis to which Dr. Horton contributed. Thank you very much for joining us today, Dr. Horton.
FAIR USE NOTICE – For details click here