Can planting trees save us? Describing the Impact of the United States Mid-Century Strategy for Deep Decarbonization on Forestry and Land Management Policies from now through 2050

Will Hackman

Abstract: The United States Mid-Century Strategy for deep decarbonization (MCS), released late in the Obama Administration, provides a vision for aggressive greenhouse gas (GHG) emissions reductions over the next three decades. The MCS goal is an economy-wide net GHG emissions reduction of 80%-100% below 2005 levels by 2050. While the Trump Administration has rolled back some of the climate change mitigation efforts initiated under previous administrations, the MCS nevertheless remains a valuable assessment of strategies the U.S. will need to eventually return to in order to achieve long-term goals consistent with international climate agreements like the Paris Agreement. This paper focuses on evaluating the MCS goal of increasing the U.S. carbon “sink” by 40-50 million acres and the role that efficient, effective, and climate-smart U.S. land resource management policies will play. Land management choices over the next 30 years will be critical to achieving U.S. climate commitments. The policy implications on both public- and private-sector land managers of this large-scale carbon sink expansion are numerous and will need to balance future needs for the variety of goods and services U.S. lands provide, including: food, wood products, energy, and living space.

Keywords: U.S. Mid-Century Strategy, decarbonization, greenhouse emissions land management policy, climate

I. Introduction

Current best-case scenarios for renewable energy deployment over the next few decades fall short of where they need to be to reach global climate sustainability goals (“2100 Warming Projections” 2018). Governments have the technological capability to eliminate fossil fuel usage, but they are not willing to put those plans in motion fast enough. Traditional energy (coal, natural gas, and oil) is still the dominant fuel source in almost every projection through mid-century, in large part due to the massive investments that have already been made (Nyquist 2016). World energy demand is also growing rapidly as developing countries industrialize. Between now and 2040, global net electricity generation is projected to increase by 45%, and fossil fuels, still the cheapest energy source in many countries, are on track to meet a large part of that demand (“Annual Energy Outlook” 2019).

Unless there are immediate and dramatic worldwide shifts in energy usage, there may be no way to avert catastrophic global warming without technologies that remove carbon dioxide (CO2) from the atmosphere. These are known as “negative carbon” technologies (“Geoengineering” 2019). Negative carbon technologies are included in 100 of the 116 scenarios that the Intergovernmental Panel on Climate Change (IPCC) – the world’s leading authority on climate science – modeled to keep global average temperature in line with the goals of the 2015 international climate agreement known as the “Paris Agreement.”

The Paris Agreement necessitates that global average temperature be kept below 2°C of warming, over pre-industrial levels, by the year 2100 (“Summary for Policymakers” 2014). This is achieved through “deep decarbonization” of the world’s economy by the middle of this century. Article 4, paragraph 19, of the Paris Agreement calls on all signatory countries to “formulate and communicate long-term low greenhouse gas emission development strategies,” for the purpose of this deep decarbonization (“Communication of Long Term Strategies” 2019).

The United States plan for deep decarbonization is called the “Mid-Century Strategy” (MCS) and it calls for U.S. economy-wide net greenhouse gas (GHG) emissions of at least 80% below 2005 levels by 2050 (“Deep Decarbonization” 2016). The U.S. MCS is the culmination of decades of policy conversations at the domestic level, international negotiations, and ever-increasing scientific understanding behind the challenges posed by climate change. Over 110 pages, the MCS divides policy priorities into three categories: transforming to a low-carbon energy system; sequestering carbon through forests, soils, and carbon dioxide (CO2) removal technologies; and reducing non-CO2 emissions. For each of these categories, well-researched policy plans are detailed with projection scenarios showing multiple pathways through which these policies might help achieve the MCS’s long-term emissions reduction goals.

This paper focuses on the second MCS priority, describing the impact of increasing U.S. forests and grasslands as a tool for carbon sequestration (i.e., negative carbon). The MCS goal in this regard is 40-50 million acres of reforestation by mid- century. Expanding U.S. forests and grasslands by such a large amount is a challenging task, but one that is modeled to potentially offset up to 50% of U.S. GHG emissions. This paper discusses the policies required to achieve this goal and what implications they would have on government land managers and private landowners.

II. Background

In 2007, U.S. annual CO2 emissions peaked above 7 gigatons and have been steadily declining since “Greenhouse Gas Inventory” 2019). The United States has now reduced total carbon emissions by more than any other country. From 2005 to 2015, U.S. emissions declined by 622 million metric tons (MMT); a 10% reduction (Rapier 2016). However, to meet the initial U.S. goal under the Paris Agreement, the United States must continue to significantly reduce GHG emissions over the next few years – reaching 17% reductions by 2020 and 26%-28% reductions by 2025 (relative to 2005) (“NDC Registry” 2019).

There have been many contributors to the reduction of CO2 emissions and other GHGs in the United States over the last 10 years. Emissions from coal-fired power plants have decreased as natural gas has become the primary source of electricity generation. In 2005, coal produced roughly 50% of U.S. electricity generation and natural gas around 20%. In 2017, coal had dropped to 30% of the domestic energy share and natural gas had increased to 31%. Renewable energy has also been growing rapidly. In 2017, all zero-emission sources – all forms of renewable energy, hydropower, and nuclear – accounted for 37% of U.S. energy generation (“Electricity: Current Issues and Trends” 2019). These dramatic shifts have reduced energy-sector emissions so much that transportation has now matched energy as the largest GHG emitting sector in the United States. Additionally, because of federal policies such as the CAFE (Corporate Average Fuel Economy) standards, transportation sector emissions over the last 10 years have also dropped around 10% (“Fast Facts” 2019).

While U.S. CO2 emissions reductions indicate positive trends, much more will need to be done to meet Paris Agreement 2025 targets and beyond. Increasing the U.S. carbon sink (i.e., forests and grasslands) will be critical to offsetting the emissions we cannot fully reduce in order to achieve our mid-century deep decarbonization goals.

In 2014, U.S. forests, grasslands, and other natural carbon sequestration sources sequestered 762 MMT of CO2 which offset around 11% of total GHG emissions (MCS, 69). As mentioned in the introduction, if the United States achieves its MCS goal of expanding current forests and grasslands by 40-50 million acres that could offset up to 50% of GHG emissions by 2050. This is because trees and grasses take CO2 in through their leaves and stalks. Through photosynthesis, oxygen is released back into the air and the carbon is transferred or stored in their trunks, limbs, and roots. However, when a tree dies and decomposes or is cut down and burned, the carbon is released back into the atmosphere, which contributes to global warming (“Forests and Carbon Storage” 2019).  

At the international level, the role of activities that promote carbon sink expansion is recognized under Land Use, Land-Use Change and Forestry (LULUCF) discussions. Climate-smart land management policy proposals and country-level carbon sink expansion strategies form key components of yearly climate negotiations. According to the United Nations:

The rate of build-up of CO2 in the atmosphere can be reduced by taking advantage of the fact that atmospheric CO2 can accumulate as carbon in vegetation and soils in terrestrial ecosystems...the world's forests and other wooded lands store more than 485 gigatons (1 Gt=1 billion tons) of carbon, 260 Gt in the biomass (53%), 37 Gt in dead wood and litter (8%) and 189 Gt in soil (39%) (“Land Use” 2019).

III. Policy proposals

From 1987 to 2012, U.S. forests expanded by roughly 1 million acres annually. From 2006-2011, federal agencies helped stimulate expansion by tree planting on over 300,000 acres annually (MCS 10). To reach the MCS goal, however, annual reforestation and afforestation would need to roughly double. In addition, since it takes time for trees to grow and reach their full carbon sequestration potential, much of the planting needs to happen in the short term. The MCS projects that 2.7 million acres of forest expansion is needed annually from now through 2035 to reach the 2050 goal.

The policy implications for government land managers and private landowners from achieving 40-50 million acres of national reforestation are numerous. U.S. forestland produces a variety of goods and services essential to the economy. Residential development and agriculture are large drivers of forest loss. A lot of U.S. energy production, including 40% of coal production, comes from federally-managed lands (“American Energy” 2019). Any plan to increase forests will need to carefully balance wood and food production, living space, and energy needs over the next few decades. To that regard, this paper makes the following six policy recommendations:

1. Fully implement the USDA Building Blocks for Climate Smart Agriculture and Forestry. This will help to reduce GHG emissions, increase carbon storage, and generate clean energy on existing private and agricultural lands.

2. Pass federal incentives to expand “precision agriculture” on private cropland that helps to increase perennial grasses and agroforestry.

3. Promote large-scale expansion of bioenergy with carbon capture and storage (BECCS) on both public and privately-managed lands. The United States could then use BECCS as a critical compliance mechanism in meeting our commitments under the Paris Agreement.

4. Put a national price on carbon dioxide emissions.

5. Extend the business Investment Tax Credit (ITC) for solar installations and the Production Tax Credit (PTC) for wind installations.

6. Ensure all nuclear power plants retiring over the next 20 years are replaced with new nuclear power plants.

 
IV. Discussion and analysis  

Policy recommendations 1-3 are suggested within the framework of expanding the U.S. carbon sink from its current rate of 1 million acres annually to the needed MCS projection of 2.7 million acres annually from now through 2035. Federal stimulation will play a key role in this expansion but private sector coordination is also required. These first three recommendations ensure continued economic profitability on private lands that may be impacted by land use management changes.

Forest expansion on non-federal lands

When European settlers first arrived in the early 1600s, forests covered roughly half of what would become the landmass of the United States (“Old-Growth Forests” 2019). Today, even with reforestation efforts, total forest percentage is down to around 30% (with nearly all forest cover “new growth” forests – as opposed to “old growth” which has almost entirely been lost) (Ibid). That equates to a net reduction of approximately 257 million acres of forest due to U.S. industrialization (“Forest Facts” 2019). That is more than three times the size of the total acreage under management by the National Park Service (Ibid). It also equates to an incredible amount of stored carbon released into the atmosphere.  

Much of U.S. deforestation was done for agricultural and residential needs (Ibid). In places where development directly converted forests into farms or neighborhoods, the land is now under private ownership. This presents challenges in expanding forest land and careful coordination with private landowners and other non-federal entities is needed. Adopting the ten U.S. Department of Agriculture (USDA) “Building Blocks for Climate Smart Agriculture and Forestry,” created in 2015, would help set the framework for correcting years of policies that promoted deforestation and development.

The USDA building blocks include planting more trees in urban locations, constructing more large buildings out of wood, and encouraging agricultural partnerships. One example the MCS provides for the latter is Iowa:

In Iowa alone, an estimated 27% of cropland, or 7 million acres, may not be profitable in commodity crop production but could be well-suited to perennial grasses or agroforestry. Focusing nationally on such areas could minimize land use competition and help increase rural landowner incomes while delivering environmental benefits like improved soil health and reduced nutrient runoff (MCS, 12).

The Iowa example is one of many public-private partnerships that will be required to balance the multiple needs of U.S. lands while ensuring rural economies aren’t devastated by large-scale, climate-smart land use changes. Biomass energy might be another large-scale strategy worth considering.

There is an estimated 31 million acres of farmland that MCS models could be used to grow energy crops like perennial grasses (MCS, 76). According to the Biomass Energy Resource Center (BERC) in Burlington, Vermont, perennial grasses were used on the prairie for heat before the industrial revolution and in places with little forest land – a process that became known as “Prairie Coal.” These grasses sequester a lot of carbon in their roots and soil and are easy to grow. In particular, BERC research shows switchgrass has a very efficient energy output to input ratio. BERC has also concluded that, “one acre of farmland is capable of producing an average annual yield of herbaceous biomass sufficient to meet the annual space- and water-heating needs of an average home” (“Grass Energy Basics” 2019).

Traditional wood is another large-scale biomass energy source with carbon sequestration potential – if the carbon is captured when burned. This process is known as Bio-Energy with Carbon Capture and Storage (BECCS). The MCS estimates that up to 50 million acres of trees could be planted on existing agricultural land for the purpose of BECCS. This would not only provide energy and carbon sequestration but also needed revenue for rural areas, all without impacting production (MCS, 78). This is known as “precision agriculture” or “agroforestry” and the MCS claims it could, “improve soil quality, water and nutrient retention, and crop yields, all with minimal competition for land use” (MCS, 76). This approach of balancing yield and economics will be crucial in land use conversations with private landowners.

Forest expansion on federal lands

There is much potential to enhance the U.S. carbon sink through better private sector coordination, as described. However, better federal land management will also be crucial. Currently, 28% of the total U.S. land mass is federally managed lands (“Forest Facts” 2019). With existing agency jurisdictions and management plans already in place, it becomes easier to implement large-scale projects to enhance the carbon sink on federal land than private, and there is more accountability in tracking results. Additionally, the carbon sequestration potential of federal grasslands and forests are already tracked annually in national GHG inventories. In 2014, U.S. forests, grasslands, and other natural carbon sequestration sources sequestered 762 MMT of CO2 (MCS, 69).

Many of the same practices mentioned in section 3.1 can also be implemented on federal lands and scaled up rapidly -- such as BECCS. Using BECCS to reduce global carbon emissions was included in over 100 of the 116 scenarios modeling ways to keep global average temperature below 2°C by the IPCC. Models projecting large-scale utilization of BECCS could remove up to 616 gigatons (616,000 million metric tons) of global CO2 from the atmosphere by 2100 (“Rising Cost” 2015). At the federal level, the United States could potentially pursue land-use policies to dramatically expand BECCS. The government could then use these policies as another critical compliance mechanism in meeting our commitment under the Paris Agreement, and as a short-term offsetting bridge as we struggle to fully transition our energy and transportation sectors to clean energy sources.

As climate change gets worse each year, federal land management challenges increase. Increased droughts and wildfires, invasive species and insect attacks (such as bark beetles which have leveled 46 million acres of U.S. forest land), and weather events all threaten the future of U.S. forests (“Fourth National” 2019). Federal agencies that will be needed to promote reforestation and afforestation under the MCS goals are now spending an increasingly larger percentage of their annual budgets fighting these factors. According to a 2015 U.S. Forest Service (USFS) report, fire made up 16% of the agency’s annual budget in 1995, 50% in 2015, and (without funding increases) fighting fires could exceed 67% of the agency’s annual budget by 2025 (“Rising Cost” 2015). If that happens, agency funding for all non-fire programs could be reduced by $700 million. This squeeze on federal resources has already resulted in a reduction of all non-fire USFS personnel by 39% (Ibid).

A reduction of the very resources and human capital needed to fight climate change, due to climate change, is not unique to the USFS. The federal government as a whole is spending an increasingly larger percentage of its annual budget addressing the many challenges climate change adaptation poses. Fighting fires is just one item on a long list that includes responding to natural disasters, increased crop and flood insurance claims, coastal resiliency projects, safeguarding the energy grid and other national security interests, and repairs to damaged federal infrastructure. According to the Government Accountability Office (GAO), climate change will exacerbate these threats and increase costs to the federal government by billions of dollars a year (“Climate Change” 2017).

This is all to say the sooner the federal government acts the better. It is in the government’s own self-interest to address climate change before the costs bankrupt program budgets. And, as the MCS highlights, there are many opportunities for economic growth while pursuing needed policies. 

Further discussion points

Policy recommendation 4 is important for several reasons. Putting a price on carbon utilizes the power of the market to incentivize emissions reductions in the most effective and economic ways. Achieving deep decarbonization by mid-century will carry significant costs to every sector of the U.S. economy. Implementing a carbon price can actually help reduce those costs in the long run. According to the MCS, long-term cost projections associated with national carbon emissions reductions were two to five times higher without an economy-wide carbon price than with (MCS, 30). A carbon price is also necessary for many of the land use changes called for under the MCS and to encourage private landowners to pursue policy recommendations 1-3.

Many forms of carbon pricing structures have been proposed in recent years, all with their pros and cons. A Department of Energy analysis shows that a price that starts around $20 per metric ton and increases steadily would be adequate to achieve most of the long-term CO2 emissions reductions goals contained within the MCS (MCS, 82). Whatever the ultimate policy becomes, there is no doubt about its necessity in allowing the United States to reach long-term sustainability goals. 

Finally, while not directly related to land-use changes, policy recommendations 5-6 are included in this paper as an important reference to maintaining existing policies that incentivize CO2 emissions reductions in the short term as other longer-term policies are developed. The business Investment Tax Credit (ITC) for solar installations and the Production Tax Credit (PTC) for wind installations have significantly helped to reduce barriers to entry in the energy sector. In recent decades, and in large part to these federal tax credits, there has been huge growth in the United States solar and wind industries. However, as of 2017, wind and solar still only accounted for just 6.3% and 1.3% of U.S. energy supply, respectively, while fossil fuels supplied 63% (“U.S. electricity” 2019). The current scale of renewable energy deployment needs to increase to reach global climate goals. Yet, the federal government is now gradually phasing the ITC and PTC down over the next five years, which could potentially lead the industries to stall.

Regarding nuclear power, many plants are nearing the end of their lifespans and either need to be updated or replaced by new systems. According to a 2016 study by the Rhodium Group, if all “at risk” U.S. nuclear plants retired by 2030, GHG emissions from the U.S. power sector would double from 2020 to 2030 (Larsen and Herndon 2016). Nuclear power supplies 20% of total U.S. energy and 60% of all our clean energy. Continued nuclear generation at current levels, or expanded nuclear generation, is included in every deep decarbonization scenario under the MCS. Even by implementing best-case carbon sink expansion scenarios discussed in this paper, the United States will not be able to achieve our deep decarbonization goals, meet the goals of the Paris Agreement, and achieve climate sustainability, if existing policies that promote all forms of clean energy are not maintained.

V. Conclusion

A 2016 Shell Oil report concluded that to achieve global electricity sector decarbonization by mid-century, the energy mix would need to be at least 40% wind and solar, 20% nuclear and hydroelectricity, 15% bioenergy, and 20%-25% fossil fuels with carbon capture and sequestration (and mostly natural gas, not coal or oil). According to Shell’s report, this would require a “complete turnaround from today, where hydrocarbons constitute more than 80% of our [global] energy system” (Stern 2018). 

The United States will face monumental challenges in achieving this complete turnaround in our energy mix. Even with best case scenarios in energy, transportation, agriculture, and land use, many factors could slow progress. Now that the United States has become an exporter of coal, oil, and natural gas, domestic fossil fuel production may still increase to meet expanding global demand, even if domestic demand decreases. The United States is resource-rich, with one-fifth of the entire world’s coal reserves and 34% of global technically-recoverable natural gas (“How much coal” 2019). The United States is now the largest producer of natural gas and oil in the world (including crude and petroleum hydrocarbons).[1] It is plausible that new policies that increase fossil fuel production under the current administration, or any future administration, could contribute to a rise in global CO2 emissions. We might already be observing the beginning of this effect. According to the U.S. Energy Information Administration, energy-related CO2 emissions declined in 2017 by 0.7%, but will increase by 0.9% in 2018 and by an additional 1.0% in 2019 (“Energy Outlook” 2019).

Clearly, there is a lot of uncertainty regarding the impact the current U.S. administration may have on efforts to mitigate climate change. What is clear, however, is that pursuit of the MCS goals must resume if we are to achieve our Paris Agreement commitments. The MCS is not a platform for any one administration. It is a set of tools for our entire society to move toward climate sustainability over the next few decades. It is also clear that climate inaction by the United States will be impossible to maintain in the long term. Global alarm and pressure is building. Markets are shifting. Every country on earth has signed the Paris Agreement – including the United States which, despite some misleading reporting, is still in the agreement. 

At the same time, the United States has many opportunities to consider if we are able to move toward our MCS goals. As discussed, creative new agricultural practices could result in tens of millions of acres of farmland not only being added to the U.S. carbon sink but reimagined into more profitable ventures. The hundreds of millions of acres under management by federal agencies could see similar benefits.

Expanding U.S. forests by 40 to 50 million acres by 2050 would recover one-third of all U.S. forestland lost since 1850. This is a daunting task, but federal land management agencies theoretically have the tools needed to get the job done. The U.S. Forest Service directly manages 193 million acres and “supports sustainable management” on 500 million acres of private, state, and tribal forests. The Bureau of Land Management manages another 250 million acres and the National Park Service manages 84 million acres (“Forest Facts” 2019). Not all of this acreage is suitable for forest or grassland, but it is plausible that a coordinated effort between federal and state agencies, as well as private and tribal land owners, could result in the needed carbon sink expansion. The path to increasing the carbon sink is viable through a variety of different scenarios all of which benefit society and the economy.

The year 2050 might seem a long way off, especially in the context of policymaking. However, the importance of urgent action over the next few years cannot be overstated. Recent research published in the journal Science shows that in order to curb global temperature rise to around 2°C above pre-industrial levels by 2100, fossil-fuel emissions can peak by 2020 and need to fall to close to zero by 2050 (Rockström et al. 2017). A recent joint report from the International Energy Agency and the International Renewable Energy Agency supports this claim. According to the report, to have just a 66% chance of avoiding 2°C of warming, urgent action on a global scale is required and comprehensive policies need to be introduced immediately.

U.S. federal forestry and land management policies initiated now that promote carbon sink expansion could be the determining factor in whether or not the United States reaches our climate goals. While long-term structural changes are needed in energy, transportation, and indeed across every corner of the global economy, this will take time. Increasing the carbon sink in the short term may be our best hope to offset the emissions we ultimately can’t reduce. We must buy ourselves time to fundamentally reshape society’s relationship with energy production and consumption and, by doing so, have a chance at avoiding climate disaster.

[1] EIA data on US as the world’s top producer of petroleum and natural gas hydrocarbons can be accessed through (https://www.eia.gov/outlooks/ieo/exec_summ.php).