An environmental conservation expert discusses how new research will play a major role in promoting a greener future
Image source: Christoph Nolte, Boston University.
For decades, scientists have been warning of the potential future impacts of global climate change, including more frequent wildfires, longer periods of droughts, and sharp increases in the number, duration and intensity of tropical storms. Since the start of 2020, we have witnessed natural disasters in record numbers, from wildfires that ravaged California and Colorado, to most consecutive days with temperatures reaching more than 100 degrees in places like Arizona. Environmental concerns are constantly creeping into a broader national stage: climate change and conservation issues received more attention during the first presidential debate on September 29, 2020 than any other presidential debate in history.
When it comes to the topic of environmental protection, Boston University’s Associate Professor of Earth and the Environment, Christophe Nolte, is hardly a newcomer. He has spent most of his academic career studying the effectiveness of conservation, asking key questions about where to make a concerted effort, and what difference it makes for our world as a whole. To inform future decisions on conservation policy, Associate Professor Nolte has now created the first high-resolution map of land value in the United States – a tool that he says will better estimate conservation costs, inform policy recommendations, and help peer academics conduct research on rebuilding and protecting what remains. Of our natural resources and biodiversity within our ecosystems. Boston University interviewed Nolte to learn more about his research and impact.
It created the first high-resolution map of American Earth value. What prompted this research?
I was dissatisfied with the quality of the cost data in conservation research. Land conservation decisions about swaps. If we want to preserve forest carbon on Earth, species habitats intact, make wetlands, or beautiful landscapes, conservation usually means giving up on something: the benefits from alternative land uses. Arguments are common for further conservation. For example, Harvard’s EO Wilson suggests that 50% of the Earth should be protected. However, these points are incomplete if you are not also explicit about what to give up and where, who will win who loses, and who decides.
Ignoring the costs can cause us to ignore the negative effects of regulation, which are often borne by those without a voice. In the case of voluntary conservation programs, ignoring the cost can mean that we will end up with a proposal, but the funding is not sufficient. If we are to make informed societal decisions about conservation efforts, we need reliable and publicly available estimates of their cost.
Unfortunately, it is difficult to get good cost-to-save data. Conservation organizations do not freely share their financial records. Land prices can be good alternatives to cost-of-conservation data, but this data is valuable, sensitive, and not publicly available in most countries. So when large-scale land price data in the United States became available to academics for free for the first time, this created an exciting opportunity to create the first high-resolution map of land value and see how much to predict the cost of conservation.
What data did you use to create this map?
There are several data sets behind this map. Perhaps the most important is the nationwide database of properties and their sales. That dataset came from Zillow, the real estate company, which collects data from public records and makes it available to academics and nonprofits. In my research group, we developed a system that links this data to digital maps of property boundaries. This allows us to obtain detailed information on the characteristics of the land: buildings, terrain, land cover, road access, water access, flood hazards, local demographics, nearby facilities, etc. This data is fed into a machine learning algorithm, which learns to predict sales prices through its knowledge of the characteristics of each property. After training the algorithm, it allowed it to predict sales prices for each property in the country. The result is this map.
What does this map tell us about the costs of preserving the environment? Why is it necessary to have accurate data on the value of land?
It found that most of the cost estimates that were used in the literature underestimated the cost of conservation in the United States. This underestimation is especially great near cities, where land values tend to be much higher than what previous agents suggested. In other words, this means that we will need much higher levels of financing than previously assumed if we are to achieve certain environmental goals, such as protecting all floodplains from development or protecting species’ habitats in the face of climate change.
How can your research help educate policymakers about future conservation plans and priorities? Why is this important?
I think it is good to be realistic about what a certain level of funding can achieve. For example, in August, Congress passed the Great American Outdoor Act, a landmark bipartisan bill that provides $ 4.5 billion in federal funding for land protection. If previous conservation cost estimates are correct, this budget can help get us to the proposed habitat protection needs for all species in the United States. However, the new cost data indicates that even this unprecedented budget covers only 5% of what is actually required. This is a big difference!
More accurate cost data can also change recommendations about where your conservation investment should go. When I reproduced the last work, about a quarter of the sites recommended for protecting species had shifted from site to site, say, from expensive Long Island to less expensive southeast Massachusetts. While this result should be taken into account, it does show that the quality of cost data is important. The good news is that the cost map has now been published, so anyone can incorporate it into their analyzes and revisit their earlier findings.
How can people best use this data when thinking about preserving the environment as it relates to their daily lives?
Data on the cost of preservation helps us be realistic about the actual size and severity of the conservation problem we face as a society. Many of us feel positive about the benefits that protected lands provide. However, we’re not all willing to make sacrifices to protect these lands, whether that’s by reducing our environmental impacts, or by voting in favor of local land use regulations or measures that increase taxes to fund conservation. In the midst of this, we are exposed to advertisements indicating that we can “offset” our environmental impacts very little cost – for example, we can become “carbon neutral” for a few dollars by purchasing carbon offsets when we fly.
A close look at the many inexpensive compensation schemes indicates that they do not reduce emissions much. But its presence has the side effect of us raising our hopes that there may be a cheap way around the conservation problem. In fact, everyone’s profit situations are rare and the trade-offs are real. This may be difficult to accept, but we should not ignore it, even if we desperately want to be satisfied with our levels of consumption.
Although the costs are much higher than the original estimates, why is conservation still an important investment?
The answers to this question have two dimensions: science and values. Science helps us understand the consequences of our actions. If we want to mitigate climate change, we need to reduce greenhouse gas emissions. Land conservation can help, for example, by preserving forests and wetlands, reducing urban sprawl, or increasing local recreation opportunities. If we want to prevent species extinction, we need to protect and restore threatened habitats, conserve lands in a climate shelter, and build ecological corridors, so that species can move as temperatures rise. If we want to avoid flood damage, we must protect more floodplains from development.
Science tells us about the consequences of our actions, but it doesn’t tell us what to do. The most difficult question is to what extent we, as individuals and as a society, care about these outcomes and what we are willing to give up. There are 8 billion of us. What each of us cares about is shaped by our diverse beliefs and morals, our upbringing, the people in our lives, the media we consume, the things we enjoy doing, etc. Given my affiliation, it might come as no surprise to feel positive about policies that reduce our collective human footprint, but it is unwise to raise the individual worldview to a record high. Instead, I think what is desirable is that there is broader societal protection for informed citizens who make those decisions together. My job, along with thousands of other colleagues, is to provide tools that can help us clarify what is at stake.
Are there any other surprising results? Could this data have other applications in areas outside of protection (for example, real estate)?
I was surprised by the predictive power of the algorithm. As a verification step, I tested whether the estimated land values can predict the actual cost of the more than 4,000 public land conservation purchases that were distributed across the country. I had expected that the expectations would beat the agents they had used in previous studies, which they did. To my surprise, however, the forecasts outperformed the tax assessors’ estimates. Tax evaluators are tasked with estimating the value of all real estate in a particular jurisdiction for tax purposes, and part of this process often involves estimating the “fair market value” of each property. Since the evaluators operate locally and know their area much better than the national dataset, I expected their estimates to significantly exceed my estimate. Instead, however, I found that my accuracy was 29% more accurate. This raises the question of why these differences exist and opens up interesting new avenues for scrutiny of existing methods of taxing property.
What do you think is the most important protection issue facing the world today?
It would be difficult to answer this question without referring to climate change. It affects everything else we think about conservation. If we don’t stop climate change, then preserving species in their present location will not preserve them in the future. It will be difficult to control future floods and sea level rise. And we worry a lot about preserving forests and wetlands today because we know their loss fuels this fire. On a project level, if you want to convince people that conservation is a good idea, talking about rare or interesting species, beautiful landscapes, and recreational opportunities may make you more attractive. But many of these efforts may be a drop in the sea if we don’t deal with this huge elephant in the room.
What do you hope people will take from this project? What are you planning to look for next?
For me, my students and colleagues at universities across the country, the synthesis of this rich database has created new opportunities for empirical research that would have been unimaginable only a few years ago. We currently support research on economic risks from floods, oil spills and hazardous wastes, the economic impacts of land systems, the benefits of water quality and emissions reduction priorities from protecting forests. My curiosity is mostly about projects that help people protect the places and species they love: identifying protection opportunities, scrutinizing the effectiveness of current programs, and reducing information barriers to accomplishing preservation. It’s an exciting time to do this research, and I am delighted that so many wonderful fellows across the country are interested in advancing the frontiers of knowledge together.