Climate Change: Might Present Harm Improve Policy Prospects?
If climate change harms those living today, enacting policy to address it may be more likely.
How will climate change impact outdoor recreation? RFF’s Casey Wichman discusses work examining data from 27 million recreational bike-share trips across 16 North American cities.
RESOURCES: We often hear about research on how climate change will affect things such as economic output and agricultural productivity. Your recent work with Nathan Chan (of the University of Massachusetts Amherst) focuses on a topic that doesn’t yet seem widely addressed—how climate change could impact activities outside of traditional economic markets, looking specifically in this case at how people spend their leisure time.
CASEY WICHMAN: That’s right—there’s been a lot of work in areas where we have reliable data. But we don’t necessarily have much data on things such as outdoor recreation or ecosystem services, because these types of “nonmarket” goods and services aren’t generally accounted for in the same way as those commonly traded in markets. This is an important distinction because if climate change impacts are measured only in terms of gross domestic product (that is, market impacts), then that misses a huge portion of goods and services that people value. To construct optimal climate policy, we need to have a full accounting of how climate change will affect economic welfare.
We used a somewhat novel approach by assessing data from bike-share programs to help shed light on how much people enjoy recreating outdoors when the weather is nice. Millions of recreational bicycle trips are taken each year using these programs, which exist around the world and make bikes available to users throughout a city. People can take them out, ride around, and then leave the bikes at any number of stations.
Many bike-share companies have been generous in making their data publicly available online. Across a wide array of cities, this offers a really rich data set: we know where people traveled and how long they had a bike checked out. For this study, we looked specifically at data on bike-share usage in 16 cities across North America with publicly available data, from Mexico City to San Francisco to Montreal.
RESOURCES: If the weather isn’t as cold as it usually is, we can imagine that people might be more inclined to get outside and ride a bike. But sometimes it’s really hot and people might prefer taking a car or simply staying inside instead of cycling. What did you find? Does one of these effects dominate?
WICHMAN: It’s somewhat theoretically ambiguous whether climate change would increase or decrease people’s demand for outdoor for recreation because of these competing effects. On really hot days, people don’t want to be out riding bicycles. It’s uncomfortable. But it’s also uncomfortable on really cold days.
So we sought to look at that question empirically, and our findings are fairly surprising—indicating that people dislike cold temperatures much more than they dislike hot temperatures. It suggests that as we experience more hot days each year in the future as a result of climate change, we might not see a big negative impact on outdoor recreational activity.
We could see an increase in the benefits associated with climate change when it comes to outdoor recreation—but the story isn’t that simple.
RESOURCES: Usually when we hear about the effects of climate change, it’s bad news. Is it the case here that there may be benefits from a warmer climate that could offset some of the negative impacts?
WICHMAN: That’s absolutely true. And it’s something we can’t understate—climate change will have enormous economic costs, in the United States but also globally. However, as we consider expected increases in more moderate temperatures during shoulder seasons, our research points to something of a silver lining when it comes to climate change. Imagine a March day in Washington, DC: it’s probably pretty grey. But what if, instead, that day in early spring is 60 degrees and sunny? Will you be more likely to go spend recreational time outside compared to a cooler, darker day? Probably. And there are huge benefits from going outside and recreating. So we could see an increase in the benefits associated with climate change in this context.
But the story isn’t that simple. We found mixed results across the United States in how warmer temperatures may affect how much downtime people want to spend outside. Our research indicates that some regions will see reduced demand for outdoor recreation, particularly in hot, southeastern states. States in more temperate regions, such as the Midwest and Northeast, will see bigger gains in demand for outdoor recreation induced by climate change.
RESOURCES: Your thought experiment doesn’t require a stretch of the imagination for people familiar with the DC area—we’ve had those unseasonably warm days already in 2018 as well as in past winter seasons, and the same is true for other regions across North America. We should say, though, that we could never attribute the weather on any one day specifically to climate change, broadly speaking. But people notice when the weather is unseasonably warm, and this study shows how those days can help demonstrate the impact of climate change on leisure.
WICHMAN: Right—and it’s important to note that there will be an increase in the number of natural disasters associated with climate change, more frequent hurricanes and floods and things of that nature. This research doesn’t really capture that, however. It examines day-to-day changes in weather that might actually complement outdoor leisure activity.
RESOURCES: Is bicycling representative of all leisure activities? And are users of bike-share programs representative of all kinds of people?
WICHMAN: The short answer is no. And our study includes several analytical checks to assess how robust the results are (i.e., to make sure that we’re actually capturing something that does constitute recreation activity). First and foremost, to avoid lumping commuters who take bike-share trips to work into our measure of recreation demand, we base all of our estimates on data from bicycle trips that took place during weekends. We also look at which cyclists are annual members of the individual bike share programs and which cyclists are casual users. In analyzing that breakout of bike-share consumers, we see that the casual users and the annual members have almost identical responses to weather—offering confidence that we’re really capturing leisurely pursuits in this study.
And taking it one step further, this is a relationship between cycling and temperature that looks like an upside-down, asymmetric “U”, where very cold days inhibit cycling much more than very hot days. This inverse “U” relationship with respect to temperature has been identified in other settings for more general leisure activities, giving us even more confidence that what we’re capturing is actually recreation.
One last thing we examine in the paper is a completely different data set from the US Bureau of Labor Statistics’ American Time Use Survey, which catalogs how people spend their days. It’s nationally representative and it tracks everything that survey respondents do in a 24-hour period. Several detailed categories cover recreational activity. Isolating data from those categories to run through our empirical models, we find a very similar response between recreation demand and temperature as we see in our analysis of the bike-share data.
It’s worth noting that the bike-share data are extremely unique because there are so many observations that we can use to identify this relationship—over 27 million weekend bicycle trips that we can attribute as recreational activity. Using those data helps us get a better picture of what people’s responses to weather look like across very different climates in North America when it comes to how people spend their leisure time.
RESOURCES: Do seasons factor into the story? Leisure time brings to mind summer activities for plenty of people, but many also really value wintertime recreation, such as vacationing at a ski resort or playing in a local hockey league. How does your research link to cold-weather leisure activities?
WICHMAN: That’s a great point. In this study, we don’t consider winter recreation at all. Within the climate change literature, we do see research indicating that climate change will have huge negative impacts on wintertime recreation activities that depend on cold weather (e.g., skiing, snowboarding, cross-country skiing, snowmobiling, and the like). Participation in winter recreation, however, is much smaller than for warm-weather recreation. So any losses for skiing in the winter, for example, are swamped by benefits from riding a bike in the spring. In a complementary analysis, we show that the net effect of climate change on all recreation will be positive. But that’s not to say that there won’t be winners and losers within the outdoor recreation industry.
RESOURCES: Your study also monetizes these benefits. How did you go about estimating that value and what did you find?
WICHMAN: One of the things we aimed to do with this research is make the jump from examining the relatively narrow topic of bicyclists behavior to something more nationally representative. So we took our results on the responsiveness to weather of bike-share users and applied the change in recreation activity to the nationally representative American Time Use Survey, using that as a baseline to capture how much leisure time people are already spending outside, whether cycling, hiking, swimming, fishing, and so on. Combined with our projections of what the weather will look like by midcentury (between 2055 and 2060) from a group of global climate models, we can then estimate how much time people will spend recreating outdoors in the future based on a future climate scenario.
From that, we use an analytical approach known as benefits transfer—essentially, taking an estimate of benefits already identified elsewhere in the peer-reviewed academic literature that provides a value for how much people enjoy (in monetary terms) a particular activity, such as cycling. We apply that number to the expected changes in recreation demand (based on our bike-share analysis) under a future climate scenario, and can then estimate what economists call people’s “willingness to pay” for recreation benefits induced by climate change. Looking at cycling alone (specifically, recreational cycling by 2060), we expect to see an increase in the value of that activity of about $900 million. For all recreational activities covered by our analysis, we estimate that this value will be about $20.7 billion annually by 2060. And again, that represents people’s willingness-to-pay for climate-induced outdoor recreation.
We estimate that the value of climate-related outdoor recreation benefits will be about $20.7 billion annually by 2060.
RESOURCES: Help us understand that in context—$20 billion is a lot of money. How does it compare to some other estimates of climate impacts?
WICHMAN: Yes, $20 billion is a large number. Previous estimates of the impacts of climate change on recreation are around $3 billion to $4 billion per year in aggregate by 2060. We find much bigger estimates, which we think is primarily due to the high-frequency data we used in this analysis.
RESOURCES: Are there other potential applications of this work beyond looking at the effects of climate change? For example, could you use this kind of approach to measure the impact of air pollution on leisure activities?
WICHMAN: We had considered looking at that with this data. Specifically, we wanted to see if we could identify whether people choose not to recreate via bicycle when there’s particularly bad ozone or particulate matter pollution because they might be at greater risk for exposure. We’re currently looking into this but don’t have any estimates to report just yet.
RESOURCES: Another area of research you’re very involved in focuses on the social cost of carbon, a measure used by economists and policymakers to help quantify the negative effects of carbon dioxide emissions on society as well as the benefits of reducing emissions. Could the work you’ve done for this study help feed into revising estimates of the social cost of carbon?
WICHMAN: That’s a great question. To date, there has been very little research on nonmarket damages from climate change, such as those related to recreation, as we’ve identified here. But one way to estimate the social cost of carbon is to look at how carbon dioxide emissions will impact all aspects of the economy, including nonmarket goods and services, and then add up those monetary terms. So, the estimates from our bike-share study could feed indirectly into a measure of the social cost of carbon. Other areas that aren’t measured, such as the effects of climate change on ecosystem services, offer really ripe areas for future research that can help produce a comprehensive estimate of the impacts of climate change.
RESOURCES: You’ve done a lot of work with the bike-share data. Are you planning any follow-on studies to refine estimates or expand your research in this area?
WICHMAN: The bike-share data are so cool—I’ve looked at how bike-share programs impact traffic congestion as well as how users trade off their time to avoid a price increase. And here we assessed how recreational bike-share users respond to changes in daily weather. I don’t have anything planned for more work specifically on bike-share use, but the data are so great that I’m sure that I’ll be able to find some way to use them in the future.