National Climate Assessment: What Did We Learn?

To do this national climate Assessment, this national climate assessment in two parts, Volume one and volume two. We did volume one focused on the physical climate science. And I'll be going through some slides to show you highlights of that volume one. And then with that kind of baseline information, we used volume two to focus on the societal impacts of those physical changes that are being observed and that are being projected. Different volumes essentially take care of different elements of the legislative mandate in terms of what the climate assessment is supposed to be.

So volume one was released just over a year ago.

So November 2017 is when volume one was released.

It was also called the Climate Science.

Special Report, again focusing on observed changes in climate, projected changes in climate, and then all of that information was then fed into, fed into volume two. So let me go through. So the next set of slides gives you information from part one of the National Climate Assessment, the physical changes.

So first, this is just an overview. I don't expect I'm not going to go through every one of these things in detail.

But the overall picture here is that all the different lines and squiggles and graphs on here collectively paint a picture in a fairly compelling way of a warming world. The trends are moving in the direction one would expect if the world in total were warming. Temperatures going up, heavy precipitation episodes, increasing snow, decreasing Arctic sea ice, decreasing ocean acidification because of the buildup of CO2 in the atmosphere going up, sea level rise going up. So all of the trends point in the direction of a warming world. And now with the next few slides, I'll go through and kind of break it down and show you the highlights of the state state of our understanding on these key indicators. Globally, we know that the long term observations are among the most consistent and widespread evidence of a warming world. The global average temperature has increased by about 1.8 degrees Fahrenheit. That's from 1901-20. And the observational evidence does not support any credible natural explanations for this amount of warming. I'll be showing some slides about how we attribute this observed warming at the global scale to the buildup of greenhouse gases.

This was a global picture. Here is the US picture similar trend that overall you see warming, but the.

Warming is not uniform.

In fact, immediately you see some places in the Southeast where there's been regionally some even.

No warming or cooling.

The greatest warming is occurring in the higher latitudes.

Alaska, for example, is a place in the United States that is warming at the fastest rate. The northwest Southwest, also the northern Great Plains are among those regions warming the most in terms of the exact value, the temperature over the contiguous United States has increased by 1.2 degrees Fahrenheit over the last few decades and by 1.8 degrees Fahrenheit, or 1 degree Celsius, relative to the beginning of the last century. So now we start to get into the detection and attribution issue. This graph shows estimates of what's referred to as radiative forcing. Radiative forcing is basically a metric of how different factors, both human factors and natural factors, change the Earth's energy balance. A positive forcing is a warming effect.

A negative forcing is a cooling effect.

That big red bar there is the human, the anthropogenic warming, total warming, warming effect from CO2 and other greenhouse gases that have built up in our atmosphere over the years. The other smaller bars there are natural.

Forcings, changes in solar radiance, which is.

A small positive, and cooling effects from volcanic eruptions. Volcanic eruptions always cause cooling because they emit a lot of aerosols that reflect sunlight. So this shows that the human influence on the delta, the change in the energy balance on the Earth.

Over time.

Is the dominant effect. Is the dominant effect. Now, to get into this, a little.

Bit more on the.

Attribution of change to human activities. So this top panel here shows the.

Temperature change.

Simulated by climate models when only natural factors are taken into account.

The black line is the observed temperature change. We've seen a previous graph.

From all the red, we know there's warming.

So that black line shows the warming trend.

And then these other, this, this line in here is the model simulation. If you only consider the natural factors and you see it doesn't match, especially.

As you go out here, it doesn't.

Affect, it doesn't match with that observed warming trend.

But now if the models include.

The human influence, and here the models are ignoring the natural influences and only considering.

The greenhouse gas influences, there is a much better match. So it's this red line compared to the black line.

There's a much, much better match.

But of course, what you want to.

Do is you want to include all factors. You want to include human factors and natural factors.

And when you do that, the match.

Is actually quite good between observed temperature change and simulated temperature change. And this is why we are so confident that the observed warming can only be explained by human influences, that the natural factors by themselves cannot explain the observed warming trend. Okay, that was all observations. Now we're going to talk about future projections. Again, we're mandated by the act from 1990 to look out over the next 25 to 100 years. What we do and what the climate science community has been doing for a long time is we construct scenarios, scenarios that consider different ways in which the world would evolve and how those different economic demographic pathways between now and out over the future would result in, in different emission trajectories. And we made a very conscious decision early on in the process to use what have been very commonly used scenarios in the climate research world, affectionately called the RCPs, the. Representative Concentration pathways. Basically scenarios. These have been used in ipcc. Researchers have been using these. So for us, it was a very reasonable thing to do to select these scenarios to frame future projections for the National Climate Assessment.

And what we did specifically is we chose two this high one and this, this one here, RCP 8.5 and 4.5.

To talk about a future world in which greenhouse gas emissions could be very, very high, or a future world in which greenhouse gas emissions may not be so high.

There's even this really, really low scenario that we did consider in some cases.

Where the assumption is that global greenhouse gas emissions have essentially already peaked and are coming way, way down.

This is the scenario that would be.

Most consistent with, for example, the goal in the Paris Agreement to prevent global temperatures from increasing 2 degrees.

So this shows the emissions, this shows the temperature implications.

Of using those different scenarios.

Okay, so these are future projections.

Again coming from volume one of the National Climate, then used in volume two.

The top part shows future projections by the middle of the century. This is considering the lower scenario, this is considering the higher scenario. You see similar patterns, but here the magnitude is different. You see that in the higher latitudes.

In Alaska, that's where you have the most warming.

But under the higher emission scenario, you.

Just have, you have a similar pattern, but you just have more, more warming.

And then this is late in the 21st century. And here you see under this high emission scenarios, you see very, very large magnitudes of warming up, you know, 7.

8 degrees Fahrenheit there.

And then here's the picture for precipitation.

Now, generally speaking, we have more confidence in future temperature projections than we do with future precipitation projections. Precipitation, you know, how precipitation is going to change in the future is still very tricky. It's much more uncertain compared to the temperature projections, especially when you get to lower scales.

But we see general patterns where we do expect greater rates of precipitation in the higher latitudes. And actually the patterns that we see.

In the future projections are consistent with what's being observed now. We're seeing more precipitation here in the Northeast. We're seeing More precipitation at higher latitudes and we're seeing drying in the Southwest. So the future projections are essentially amplifying what we're seeing, what we're seeing currently. So these maps show how different temperature thresholds may change. What I was just showing you were kind of annual averages. But this gets into more. I feel like some of these metrics get more tangible for folks. So there are large projected changes in the number of days exceeding key temperature thresholds.

So on the left we're showing projected.

Change in the number of days that would exceed 90 degrees Fahrenheit. Here there are about 20 to 30 more days per year with a maximum temperature of over 90 degrees in most areas by mid century under the high scenario, with increases by as much as 40 to 50 days per year in.

Much of the Southeast.

Then here the blue map is showing how cold days would change. In this case there are projections that there would be 20 to 30 fewer days with a minimum temperature below freezing in the northern eastern parts of the nation with decreases of more than 40 to 50 days in much of the West.

Sea level rise I think this is.

An area where compared to previous assessments, we've made really good advancements here. Instead of just talking about global sea level rise, we're showing how sea level rise would change by region for different areas of the entire US coastline.

And these two maps show future projected sea level rise along the US coastline on the left, the lower scenario, and then the right the higher scenario in.

Both cases by 2100. So other points with sea level rise is that obviously it's not evenly distributed and that circulation changes, sinking land and Antarctic ice melt will result in greater than global average sea level rise for.

The Northeast and the Gulf coast under even the lower scenario, but greater than global average sea level rise in just about all places along the US coastline.

Even for the higher scenario.

Arctic sea ice. This is becoming kind of an iconic.

Example of the changes that are underway we are observing.

I just realized I should have put.

This in the observation part of the.

Talk, but we are seeing diminished Arctic.

Sea ice not only in extent, but in volume. In fact, over time. The Arctic used to be dominated by older multi year ice. Now increasingly much or most of the Arctic sea ice is younger one year old ice, which is in turn more vulnerable to melt.

That's what that top panel shows. And this declining trend is showing the.

Downward trend in September Arctic sea ice extent. September is the time of year when the Arctic sea ice is at its lowest, lowest, lowest extent. And you see a clear declining trend there Next time I get this talk.

Tropical cyclones, Real intense area of research.

But what our volume one said is of the national climate then used in volume two.

The top part shows future projections by the middle of the century. This is considering the lower scenario. This is considering the higher scenario. You see similar patterns, but here the magnitude is different. You see that in the higher latitudes.

In Alaska, that's where you have the most warming.

But under the higher emission scenario, you just have.

You have a similar pattern, but you just have more warming.

And then this is late in the 21st century. And here you see, under this high emission scenario, you see very large magnitudes.

Of warming up 7, 8 degrees Fahrenheit there.

And then here's the picture for precipitation.

Now, generally speaking, we have more confidence in future temperature projections than we do with future precipitation projections. Precipitation, you know, how precipitation is going to change in the future is still very tricky. It's much more uncertain compared to the temperature projections, especially when you get to lower scales.

But we see general patterns where we do expect greater rates of precipitation in the higher latitudes. And actually the patterns that we see.

In the future projections are consistent with what's being observed now. We're seeing more precipitation here in the Northeast. We're seeing more precipitation at higher latitudes and, and we're seeing drying in the Southwest. So the future projections are essentially amplifying what we're seeing currently. So these maps show how different temperature thresholds may change.

What I was just showing you were.

Kind of annual averages. But this gets into more. I feel like some of these metrics get more tangible for folks. So there are large projected changes in the number of days exceeding key temperature thresholds.

On the left, we're showing projected change.

In the number of days that would exceed 90 degrees Fahrenheit. Here there are about 20 to 30 more days per year with a maximum temperature of over 90 degrees in most areas by mid century under the high scenario, with increases by as much as 40 to 50 days per year in.

Much of the Southeast.

Then here the blue map is showing how cold days would change. In this case, there are projections that there would be 20 to 30 fewer days with a minimum temperature below freezing in the northern eastern parts of the nation, with decreases of more than 40 to 50 days in much of the West.

Sea level rise.

I think this is an area where, compared to previous assessments, we've made really good advancements here. Instead of just talking about global sea level rise, we're showing how sea level rise would change by region for different areas of the entire US coastline.

And these two maps show future projected sea level rise along the US coastline on the left, the lower scenario and then the right the higher scenario in.

Both cases by 2100. So other points with sea level rise is that, well, obviously it's not evenly distributed and that circulation changes, sinking land and Antarctic ice melt will result in greater than global average sea level rise.

For the Northeast and the Gulf coast under even the lower scenario, but greater than global average sea level rise in just about all places along the US.

Coastline, even for the higher scenario.

Arctic sea ice. This is becoming kind of an iconic.

Example of the changes that are underway we are observing.

I just realized I should have put.

This in the observation part of the.

Talk, but we are seeing diminished Arctic.

Sea ice not only in extent but in volume in fact, over time. The Arctic used to be dominated by older multi year ice. Now increasingly much or most of the Arctic sea ice is younger kind of one year old ice which is in turn more vulnerable to melt.

That's what that top panel shows. And this declining trend is showing the.

Downward trend in September Arctic sea ice extent. September is the time of year when the Arctic sea ice is at its lowest, lowest, lowest extent. And you see a clear declining trend there. Next time I give this talk, I'll move this.

Tropical cyclones, Real intense area of research.

But what our volume one said is.

That models generally show an increase in the number of very intense tropical cyclones.

In a warmer world.

So increases are projected in precipitation rates.

And the frequency of the most intense of these storms is projected to increase.

In the Atlantic and western North Pacific.

So the evidence is suggesting that. Among the strongest storms, that's where we expect to see an increase, is among the category four, the category five storms. Okay, now switching to volume two. Now this is where we get into the societal, the environmental impacts and implications of all the things we just talked about. So now what are the implications for the environment, for society of all these things? We just talked about changing temperatures, changing sea level rise, changing Arctic conditions. This volume two made a big splash.

In November of just this previous year, just this past November. One point I didn't make these assessments consistent with the Act.

These are not policy documents. So what you will not find in these documents are policy recommendations. So what should we do about greenhouse gas emissions or what should the country do for adaptation by design? We don't have any of those recommendations in this document. It's not a policy prescriptive document. But we try to be as policy relevant as possible. So you won't find Any recommendations about reducing greenhouse gas emissions. But we do have in this report examples of what is happening. We show case studies about cities and states who are undertaking adaptation options. We also have information here about what kind of greenhouse gas reduction actions are occurring across the country. So we give kind of status updates about actions that are happening. But we don't go so far as to say we should do X, Y and Z because of all this information. We consider that kind of a separate report, a separate undertaking. All right, this is, you know, a.

Little bit about the process.

Again, don't worry about the details here. Like volume one, Volume two also went through a lengthy, a lengthy review. A lengthy review process. Very early on in the process, we solicited public input to put out a prospectus to get public comment. From the get go, we wanted to identify key areas that we wanted to add or enhance. Compared to the last National Climate Assessment, NCA3, for example, we wanted more regional information. We wanted to do a better job on economic valuation. We wanted to address some topics that weren't explicitly called out last time, international aspects. And in some cases we added some new chapters. So this, the process spanned two administrations. It went through, in the end it went through public review. And like volume one, we also went through a National Academies Review. Basically for all of these big reports under this umbrella US Global Change Research Program, we put all of our big reports through National Academies Review. Just because these documents are so influential, it warrants the most rigorous peer review process that that is available to us and of course, multiple rounds of federal interagency review. And we collect and document every comment and all responses to those comments and those can be found online. So in the spirit of full transparency, you can go online and you can see, you know, how we responded to a public comment, how we responded to the Academy's comments. Here's the table of contents for volume, volume two. It's about a 30 chapter report, which is why I'm throwing so many slides at you because there's a lot here.

So here we talked about the sectors.

That the Global Change Research act requires to have.

We have all of those, but we.

Threw in some others this time around. Compared to previous assessments, we have a new separate chapter on air quality. I'm going to show results from those because I think they're very impactful, they're very, I think, important.

A new chapter on international interests, sector interactions. And then we broke up the regions.

A little differently to have more granularity.

Granularity in the regions. Risk framing.

We start out this process Thinking about what kind of guidance should we be giving to all of our authors across both the sectoral chapters and the regional chapters? We actually had a National Academies workshop to talk about this issue of risk framing. Because I think the climate change issue, the climate change problem very much is one ultimately of risk management. You're dealing with uncertain outcomes over long timeframes. So it's very much kind of a risk management kind of issue.

So, you know, out of that workshop.

And then guidance we gave to all of the authors, we gave them these kind of questions to help them write their chapter and do so in a way that we were having the most kind of apples to apples template across all of the chapters.

You know, what do stakeholders value? What's at risk in a given regions, sector or region? What outcomes do we wish to avoid? What do we expect to happen in.

The absence of adaptation actions or greenhouse gas mitigation actions? How bad could things plausibly get under a plausible set of circumstances considering certain thresholds or tipping points? This is an area where we tried to make some advancements, talking about how we have to address each of these sectors. What's going to happen in agriculture, what's going to happen in transportation, what's going to happen in water resources. Doing all that is important. But in the real world, all of these sectors interact with one another. But capturing all those interactions, you know, how drought conditions affect agriculture and how agricultural impacts might in turn affect rural economies, and how those impacts may in turn affect public health issues in rural economies. Acknowledging all of these complex interactions is very, very important. But from an analytic perspective, capturing quantifying all of these very complex interactions is really, really difficult. So I think, I would say we made some progress in this area with this national climate assessment, but I would say this is still super challenging. And I think trying to capture these kind of interactions is really important for the climate impacts community moving forward. Okay, human health. So how does climate change affect health? Well, it affects health in a number of ways. It alters exposures to heat waves, floods, droughts, other extreme events, vector and foodborne diseases, and changes in the quality and safety of food, and then stresses to mental health and well being. Here we show how continued warming is estimated to increase.

Heat related deaths.

The assessment also looks at the benefits of reductions in cold related deaths. The net outcome, however, is that it's expected that increases in heat related deaths are expected to outweigh reductions in cold related deaths. This particular graph is showing how in.

49 cities.

Just the 49 cities that were analyzed.

So if you don't see dots in.

Other parts of the country. It doesn't mean that there are no effects in that part of the country. It just means there were 49 cities analyzed. It shows changes in extreme hot and extreme cold temperatures projected to result in more than 9,000 additional premature deaths per year under a higher scenario by the end of the century, although this number would be reduced if you consider some additional adaptation options. Even for example, increasing penetration of air conditioning use, even more so than what was assumed in this case.

Air quality.

Here's a picture on ozone. Right now, more than 100 million people in the US live in communities where air pollution exceeds health based air quality standards. Unless counteracting efforts are made to improve air quality, climate change is expected to exacerbate air pollution levels here. In this case, we do have high confidence that climate change will increase ozone levels or smog essentially over much of the United States, especially over already polluted areas. The maps here are showing changes in summer averages in the maximum daily 8 hour ozone concentration. Now, particulate matter, here's a little bit of a different story. Particulate matter, this is a fine particles kind of micro particles that are small enough to get into your airways. A particulate matter accounts for most of the health impacts due to air pollution in the United States. Small changes in their concentrations can have large implications for public health here without taking into account a changing climate. The US Particulate matter levels in the United States are projected to decline by 2040 just due to air quality regulations. But the levels are very sensitive to weather conditions. The effects of climate change on the timing, intensity, duration of rainfall in particular are very uncertain and it influences the rate of removal from the atmosphere of particulate matter. So for these reasons, the net impact of climate change on particular matter is still much more uncertain compared to that previous map with the ozone. So we have a lot of confidence, more confidence in the impact on ozone levels, but less confidence in the impact on particulate matter levels. But particulate matter, you know, ultimately has the larger public health, public health impact. Forests. So over the past 20 years there's, there has been an increase in the area burned across the nation. In some cases they've been difficult to suppress and the cost of suppression has.

Also been increasing over time. This graph is showing both increase in the area burned over time, but it's.

Also showing the increase in the suppression costs over time. Water resources. The assessment talks about how water resources face considerable risk even without considering climate change. There have been gains in water use efficiency over the last 30 years. That has prevented water consumption from increasing. But there is aging and deteriorating dams and levees and these represent hazards.

With this, this graph is just showing.

One example from the Colorado river basin showing on the left there historic water supply and use. And then on the right it's showing projected water supply and demand with a potential imbalance between future supply and demand with considerable long term variability. So I'm feeling a little pressed for time and let me. Oh, that sounds interesting. So this is a map about fisheries. So there's definitely people in the audience, I don't need to tell this to you, but that ecosystem disruption will intensify as ocean warming, acidification and other aspects of climate change increase here. So differences in how species respond to physical conditions lead to changes in their relative abundance within an ecosystem as species decline or increase in abundance, colonize new locations or leave places where conditions are no longer favorable. What this figure here is showing is projected changes in fishery catches within large marine ecosystems basically out until mid mid century under the higher scenario. So under that RCP 8.5 scenario and it's showing that essentially all US large marine ecosystems with the exception of the Alaskan Arctic are expected to see declining fishery catches.

So in the Alaska, the blue is showing potential increase but decreases everywhere as.

Warmer waters are projected to shift species northward. Transportation effects here. This graphic on the right is interesting. It's showing figure shows annual vehicle hours of delay on major roads due to high tide flooding by state year and sea level rise scenario. So the, so these, so the top.

The top is kind of a low sea level rise trajectory intermediate and then extreme. And then these are different time slices. 20, 20, 26, 60, 20, 100.

So high tide flooding is already becoming a major issue along parts of the east coast and then will only be exacerbated due to, due to sea level rise. So.

Here'S an example and this is.

I think these results are. Maybe some of the more interesting advancements compared to previous assessments. Here's an example of where we've been talking about what's happening in this sector and this one. This is an example of multi sector analyses. How under a scenario is multiple sectors are impacted, but not just in physical terms.

In this case, the impacts in these.

Different sectors are monetized. So here we have dollar figures associated with projected impacts in different sectors for the United States.

And according to this analysis.

That'S in.

One of the chapters. First of all, it's showing that some of the biggest impacts in terms of these monetized damages. I'll just talk about these three Big ones right here. The three big bubbles are the biggest.

One, there is outdoor labor impacts to outdoor labor, where in some cases it gets so warm and hot in summertime that outdoor construction workers, roofers, farm laborers, you just can't work.

You just can't work. And so estimated large economic impacts, this large circle is monetized.

Through value of statistical life. The monetized damages of increased mortality due to heat. So related to that previous.

Map I showed. And then this large bubble here is.

On coastal property, coastal property loss or damage due to sea level rise.

And then this column here is showing annual damages under that high scenario. And then this scenario is showing the.

Percent of those damages that would be avoided if you went from that high scenario to that low scenario.

And that's what the different colors are in these circles. So the whole size of the circle.

Is the total damage under that high scenario.

And then this fraction of the circle.

Is how much of that damage would be avoided if you went to that lower. If you went to that lower scenario. So it essentially shows the potential benefits in terms of avoided damage if you strive for a lower emission scenario. So benefits in terms of avoided damages.

I talked about how the assessment.

Essentially takes a snapshot of different greenhouse gas mitigation activities happening across the country. The United States is a very heterogeneous place, not only in terms of the physical environment and demographics, but also our governance structure. Cities and states have quite a bit of autonomy to carry out different kinds of adaptation and greenhouse gas mitigation actions. And the assessment contains this kind of snapshot about what different states are doing.

And what different cities are doing on.

Greenhouse gas mitigation activities. I'm not going to go into the.

Details of the graphic, but there's actually.

A lot of information in there. And one thing I didn't mention, and it's particularly useful for this graphic, is that the online website for this entire report, I have to say it's quite good. So there was a whole team of people that were devoted to making this information as user friendly and as accessible and searchable as possible. So if you go online, if you're interested in the Northeast, very easy to.

Find graphics like this.

You get kind of pull outs. You can get particular information that's behind the graphic. One thing I should have mentioned up front, but this is a case where going to this graphic online will give you a lot more granular information than.

I can provide you quickly here. The regional component.

The regional chapters in NCA are a lot longer than the sectoral chapters. We made a Very conscious decision to make these regional chapters really the main focus of the report. We had stakeholder engagement workshops across the country because I think for this regional information, you really do want to hear from people who live in these regions to hear what issues they're most concerned about. So you can reflect those.

In the different regions. These are the different National Climate assessment.

Regions. So the report contains a pretty rich story for every region.

Before ending with some stuff on the.

Northeast, I thought I'd highlight what's in the report on Alaska because the observed changes and the projected changes in Alaska can be pretty extraordinary. I mentioned before that the high latitudes are warming the most. This is showing observed changes and projected changes, some factoids. So Starting in the 1990s, high temperature records in Alaska occurred three times as often as record lows. And in 2015, high temperature records were occurring nine times as frequently as low, low temperature records. If the Earth were not warming, you would expect record highs generally to equal record lows. But the record highs have been outpacing the record lows. You we still have record lows, but less. And then this bottom shows projected change focused on Alaska Ocean acidification. Because of the buildup in CO2, the oceans are becoming more acidic. It affects negatively affects organisms, corals, crustaceans, crabs and other calcium carbonate containing dependent organisms. Also in the Arctic, because the Arctic sea ice is diminishing, more ice free water essentially allows for greater uptake of CO2. So it's one of the reasons why high latitude Arctic waters are even more vulnerable to ocean acidification because of the buildup in CO2. So other unique changes happening in Alaska.

The boreal regions have experienced rapid rates of warming and falling of permafrost. Projections show that near surface permafrost will likely disappear on 16 to 24% of the landscape by the end of the century.

And the threats to indigenous peoples in Alaska, not only in Alaska, but in Alaska, it's especially acute, especially for coastal, especially for coastal villages. The rates of coastal erosion now are quite high because of the diminishing Arctic sea ice. You have more open water and with more open water, you have more wave action coming on the coast and that increases erosion which can affect these indigenous coastal communities.

So here in the Northeast.

Oh, made a note to myself to mention for you all that I think she lives just down the street here. But Ellen McCrae is a NOAA colleague who took part in this chapter and she couldn't, she couldn't be here tonight. But if folks are interested in following up with someone who worked on this, especially for the Northeast Chapter, I would refer you to Ellen McCrae, NOAA, who could be a great great resource for you all.

So just some highlights from the Northeast Chapter. One is the seasonality. So the seasonality of the Northeast.

Don'T.

Have to tell you all and I.

Grew up here so I'm with you all. So I grew up in Pennsylvania. I'm part of this Northeast team.

Seasonality of the Northeast is central to the region's sense of place, place and is an important driver of rural economies. Less distinct seasons with milder winter and earlier spring conditions are already altering ecosystems and environments. Coastal habitats, Northeast coast and ocean support, commerce, tourism, recreation that important regions way of life, warmer ocean temperatures, sea level rise and ocean acidification threaten these services.

I'm giving you the high level messages from the Northeast Chapter, basically verbatim.

Risk to Urban Infrastructure of the Northeast Urban centers and their interconnections are regional and national hubs for cultural and economic activity. Major negative impacts on critical infrastructure, urban economies and nationally significant historic sites also already occurring and will become more common with the changing climate. This is a picture by the way of a storm drain that was installed.

After Hurricane Sandy to allow for floodwaters to recede more quickly.

Human Health Concerns in the Northeast A changing climate threatens the health and well being of people in the Northeast through more extreme weather, warmer temperatures, degradation of.

Air and water quality, and sea level rise.

So health impacts are expected to vary by location, of course, age, occurrent health and other characteristics of individuals and communities. This is some analysis associating maximum daily temperature with heat related emergency room visits, how it spikes up with high temperatures and this is an analysis of under different scenarios projected number of future heat related emergency room visits.

So just want to let you know that this kind of very specific analyses are being done now for specific regions. Wrapping Up Getting close to wrapping up.

On mitigation.

Another aspect are co benefits of greenhouse gas mitigation. The sources that emit carbon dioxide and other greenhouse gases also by and large are the same sources that emit the more traditional pollutants that cause air quality problems.

So controlling these common emission sources would.

Both mitigate climate change over the longer term, but have more essentially instantaneous immediate benefits for air quality and human health.

Methane because methane is both a greenhouse gas and an ozone precursor, reductions of methane emissions have the potential to simultaneously.

Mitigate climate change and improve air quality. I'm sure folks have been kind of hearing of a methane story, but mitigating methane really is a win win for climate and air quality. There's a lot in the assessment throughout all of the regional chapters on adaptation activities that are occurring. I just wanted to talk about this kind of high level point that. So when the authors looked at activities across the board, they stated that communities are currently focused more on capacity building and making buildings and assets less sensitive to climate impacts, but that communities have been less focused on reducing exposure exposure through actions such as land use, change and retreat. And furthermore, many communities adaptation actions arise and are funded in the context of recovery after an event rather than proactively with these kind of forward looking scenarios in mind.

So I thought I'd one point to end on is how is this information being used?

It's hard when you do a big report like this. It's hard to measure its use and its uptake in society.

But this anecdote is really interesting that this is a picture of the mayor from Honolulu and standing there are a.

Couple authors of the Hawaiian chapter of.

The National Climate Assessment. It turned out that three days after the release of this assessment, the mayor of Honolulu held a press conference with some of these authors to talk about.

Climate impacts.

On their home and about the decisions that they're facing about sea.

Level rise, decisions on possible coastal retreat.

In some cases, or coastal hardening in other crucial areas.

So here's just a very kind of specific anecdote about how this information is being taken up and taken seriously by decision makers in different parts of the country. I could have a lot of parting thoughts on lessons learned and where to.

Go next, but I'll end with these.

One is that I do think, I think it's a very good thing that we have the Global Change Research act now. These are my words. These words are not coming from the National Climate Assessment.

I do think the nation should have.

An authoritative, comprehensive resource on climate science.

And future projections and sectoral and regional risks.

And I do think the National Climate Assessment fulfills this function.

But increasingly climate science needs to deliver on and address decision maker needs.

Society is faced with decisions all the time that are climate relevant over different timescales.

And I think the climate science community.

Needs to engage even more with decision makers in the private sector, government sector, understand what decisions they're facing, understand what climate relevant decisions they are making and include those folks at the beginning of the process, not at the end, don't do this report and at the end say, oh by the way, was this useful? No, I think increasingly we need to include those stakeholders at the very, very beginning of the process, identify their needs, identify their questions and then build the assessment, build the analysis around those questions so that it's not let a thousand flowers kind of bloom assessment. But increasingly, I think we need to aim for more tailored, more targeted science products, science assessments that address fairly specific decision points across different elements of society.

And then the national climate assessments, as comprehensive as they are, this is related.

To the point I just made.

As comprehensive as they are, will never.

Be all things to all people. People want to ask, well, what about my city block? Okay, after all, this is a national climate assessment. We are trying to drill down and get more and more granular information. And that's really, really important. But that going city block by city block is a lot to ask of the national climate assessment. I think that's where the national climate assessment or something like the national Climate Assessment can be the first filter and provide kind of the boundary conditions, but then it can be handed over to other folks who want to take that and then take it a step further and do their own more regionally refined, regionally tailored, tailored analysis to fit their decisions. This was a huge team effort. I'm kind of standing on the shoulders of many, many people to give this talk. This was our, I think our one and only in person author meeting that.

Brought just about everyone to together. So just like just an enormous effort.

Involving, as I said before, roughly 300 federal and non federal scientists. And so hopefully the report, I think hopefully the report serves the community well, serves the nation well. Thank you.