Reducing Air Pollution: Strategies For Forest Environments

Forests are essential for maintaining healthy air quality, and air pollution poses a significant threat to their ecosystems. Trees play a vital role in reducing air pollution through direct uptake of gases and interception of airborne particles, such as dust, ash, pollen, and smoke. They also contribute to cooling the air through evapotranspiration, which is particularly beneficial in urban areas. Additionally, forests can act as carbon sinks, offsetting the accumulation of carbon dioxide in the atmosphere. However, deforestation and the burning of trees release carbon back into the atmosphere, contributing to greenhouse gas emissions. To protect forests from air pollution, it is crucial to understand the complex interactions between air pollutants, ecosystems, and climate change.

Planting more trees

Trees also reduce air temperature, which in turn alters pollution concentrations. They reduce energy consumption in buildings, which reduces air pollutant emissions from power sources. Trees can remove multiple tons of ozone, gaseous air pollution, and particulate matter each year either through direct uptake of gases or by temporarily intercepting airborne particles.

Trees are particularly effective at removing particulate matter (PM). PM comes in the form of tiny particles of organic chemicals, acids, metals, and dust emitted from fossil-fuel-burning vehicles, factories, and construction sites. The largest of these particles measure up to 10 micrometers across (PM10s), while PM2.5s measure 2.5 micrometres across, and even smaller nanoparticle pollution exists. Fine particulate matter can easily penetrate the human respiratory system, causing lung and cardiovascular diseases or exacerbating respiratory illness.

Trees can help reduce PM through dispersion and deposition. Concentrated clouds of minuscule particles get dispersed and diluted by crashing into trees and plants. PM can also get trapped in the waxy, hairy leaves of trees and shrubs and is washed away by rain.

Trees also mitigate the greenhouse gas effect by trapping heat and reducing ground-level ozone levels. In one year, an acre of mature trees absorbs the same volume of carbon monoxide as produced from a 26,000-mile car journey. Trees are able to absorb carbon dioxide from the atmosphere through photosynthesis, reducing the 'greenhouse effect' and creating a less polluted, more sustainable world for future generations.

To tackle global air pollution, it is crucial to halt deforestation and plant billions of trees.

Reducing emissions from power plants

In April 2024, the US Environmental Protection Agency (EPA) released four rules governing greenhouse gases and other emissions from fossil fuel–fired power plants. These rules are expected to have a significant impact on carbon emissions and the US electric grid.

The first of the four rules directly addresses carbon emissions by targeting emission reductions at power plants. The remaining three rules aim to reduce other forms of pollution from coal plants. They do this by raising emissions standards for toxic metals and mercury, reducing pollutants discharged through wastewater, and setting new requirements for the management of coal ash.

New emissions standards for fossil fuel power plants

The new rules require existing coal plants and future natural gas plants to address carbon dioxide emissions in the coming years. The rules address coal plants based on how long they expect to operate. For new gas plants, the required emissions controls will depend on how much they operate over the course of a year.

Compliance methods

Utilities planning to operate a plant beyond the 2030s can comply with the rule by using carbon capture technologies. If other kinds of technologies develop over time, utilities can use them, given the compliance flexibility written into the final rules. The best way to control carbon emissions at individual power plants at present is through carbon capture and storage (CCS). The EPA estimates that using CCS technology would slash 88% of carbon dioxide emissions from power plants, preventing up to 1.38 billion metric tons of emissions over the next 23 years.

Challenges to the new rules

The new rules are expected to face challenges from Congress, the courts, and potentially from future administrations. Members of Congress have indicated they plan to use a legislative tool called the Congressional Review Act to overturn the rules. On the other hand, the rules will almost certainly be challenged in the courts, and the outcomes are uncertain. A change of presidential administration would also threaten the power plant rules.

Reducing emissions from vehicles

Motor vehicles are a significant source of air pollution, and reducing vehicle emissions is crucial for improving air quality. Here are some detailed and focused strategies for reducing emissions from vehicles:

• Choose fuel-efficient vehicles: Opt for fuel-efficient vehicles with low greenhouse gas emissions. This includes plug-in hybrid electric vehicles, hydrogen fuel cell vehicles, and cleaner-burning gasoline vehicles. These vehicles can help reduce pollution while potentially saving money on fuel costs.
• Maintain your vehicle: Regular maintenance, such as tune-ups, oil changes, and following the manufacturer's maintenance schedule, ensures your vehicle runs efficiently and cleanly. Keep tires properly inflated to improve fuel efficiency and reduce pollution.
• Drive efficiently: Driving habits can significantly impact emissions. Avoid aggressive acceleration and go easy on the gas pedal and brakes. Observing speed limits and maintaining a steady speed also reduce fuel consumption and emissions.
• Reduce idle time: Unnecessary idling pollutes the air and wastes fuel. Modern vehicles do not require prolonged idling to warm up, so turn off the engine when not in motion.
• Carpool and use public transportation: Opt for carpooling, public transit, biking, or walking whenever possible. Reducing the number of vehicles on the road directly lowers emissions and improves air quality.
• Support clean transportation initiatives: Encourage and support initiatives that promote cleaner transportation options, such as electric or hybrid vehicles and improved fuel standards. These initiatives help reduce emissions and improve air quality on a larger scale.

By implementing these strategies and making conscious choices, we can significantly reduce emissions from vehicles, contributing to improved air quality, public health, and environmental protection.

Reducing emissions from agriculture

Forests can play a crucial role in reducing air pollution, especially in urban areas. Trees can improve air quality through several mechanisms, including reducing air temperature, lowering energy consumption in buildings, and directly removing pollutants from the air. Urban forests can intercept airborne particles and absorb gaseous molecules through tiny pores called stomata on their leaves. This helps in mitigating the negative impacts of air pollution on human health, scenic views, and ecosystem processes.

Now, let's focus on reducing emissions from agriculture:

Agriculture is a significant contributor to greenhouse gas (GHG) emissions, and it is essential to address this issue to meet climate goals. Here are some detailed strategies and practices to reduce emissions from agriculture:

• Boost productivity: To protect forests and limit the expansion of agricultural land, it is crucial to increase productivity without requiring more land. This can be achieved through federal funding for research and development, improving crop yields, and enhancing livestock efficiency. For example, from 1997 to 2017, wheat, soybean, and corn productivities in the US increased by 23%, 28%, and 42%, respectively. Additionally, improvements in livestock efficiency led to a 33% reduction in land use from 1977 to 2007.
• Reduce livestock emissions: Livestock production accounts for over 40% of agricultural GHG emissions in the US. To mitigate this, farmers can use feed additives, practice rotational grazing, and select high-quality feed to reduce methane released from enteric fermentation. Additionally, improving manure management through storage facilities, nutrient management plans, and methane capture and combustion can further reduce emissions.
• Reduce emissions from fertilizer use: Synthetic fertilizers and manure contribute to about half of US agricultural production emissions. Adopting techniques like nitrification inhibitors, using microbes for nitrogen fixation, and implementing more precise fertilizer management can help reduce emissions from fertilizer use.
• Support on-farm renewable energy and energy efficiency: On-farm fuel consumption accounts for around 6% of agricultural production emissions. By improving equipment and increasing energy efficiency in farm buildings, farmers can reduce fuel use and emissions while also saving on energy costs. Programs like USDA's Rural Energy for America Program (REAP) offer grants and loan guarantees to help farmers transition to renewable energy systems.
• Stabilize and sequester carbon in vegetation and soils: Integrating more trees through agroforestry systems can help sequester carbon in vegetation. Additionally, practices such as cover cropping, agroforestry, and nutrient management planning can enhance carbon sequestration in agricultural soils.
• Reduce food loss and waste: While most efforts have focused on reducing food waste at the consumer level, it is also essential to address on-farm losses due to factors like decreased demand from the food service sector and labor shortages. Permanent programs that assist farmers in redistributing unsold food and technologies that improve supply chain linkages can help make the food system more resilient.

By implementing these strategies, the agricultural sector can play a crucial role in reducing emissions, improving resilience to climate change, and contributing to sustainable food production.

Protecting ancient woodland

Ancient woodland is one of the UK's most precious natural assets. These sites have evolved over centuries into the country's richest, most biodiverse land habitats. They are home to many scarce species, including the purple emperor butterfly, lungwort lichens, and the lemon slug. Ancient woodland also holds historical and cultural significance, providing archaeological insights into the past.

However, ancient woodland is under severe threat. Today, it covers less than 3% of the UK landscape, and much of what remains is damaged and in need of restoration. More than 1,200 ancient woods are currently at risk of inappropriate development, including housing estates, roads, and railways, which will damage ancient woodland edges, tear into habitats, or completely destroy sites.

The Woodland Trust, a group campaigning to protect ancient woodland, has highlighted a loophole in the National Planning Policy Framework (NPPF) that allows development to go ahead if "the economic benefit of a development outweighs the loss". Despite government agreement on the need to protect ancient woodland, and recommendations from the Communities and Local Government Select Committee to update the NPPF, no changes have been implemented.

To protect ancient woodland, the following actions are necessary:

• Close the loophole in the NPPF to ensure that ancient woodland is given the same level of protection as man-made heritage, such as listed buildings.
• Implement better wording in paragraph 118 of the NPPF, which currently states that development resulting in the loss of ancient woodland should be refused "unless the need for, and benefits of, the development in that location clearly outweigh the loss".
• Ensure greater enforcement of offsetting, where any loss or deterioration of ancient woodland is compensated for by equivalent gains in ecological value elsewhere.
• Establish an official monitoring system to track the status of ancient woodland and the impact of development.
• Encourage local communities to take action, as this has proven to be an effective way to protect ancient woodland, as seen in the case of North Yorkshire County Council's decision to cancel road-building plans that would have impacted the ancient woodland of Bilton Beck & Rudding Bottoms at Nidd Gorge.
• Support campaigns by groups such as the Woodland Trust and The Ancient Tree Forum, which are working to gain better protection for ancient woodland sites.
• Raise awareness about the importance of ancient woodland and its benefits to the natural environment, biodiversity, health, and recreational enjoyment.
• Work with landowners and managers to restore privately-owned ancient woodland, removing non-native trees and plants, and enabling the regeneration of native species.

Frequently asked questions