What’s the problem?

Noise pollution is a global issue. More than half of the residents of large European cities, for example, live in areas where noise levels adversely affect their health. Background noise of 60 dB is enough to raise heart rate and blood pressure and cause a loss of concentration and sleep.

City layout and building design play a key role in noise distribution. Residents with lower incomes, who live in poor quality housing, are more exposed to traffic noise.

How can this problem be fixed?

Many of the solutions are found in nature.

Vegetation in urban environments, like plant-filled rooftops, can absorb acoustic energy and diffuse noise. Tree belts, shrubs, green walls and green roofs can amplify natural sounds by attracting urban wildlife.

Urban green spaces such as public parks offer acoustic relief to city inhabitants. Pleasant natural sounds like rustling leaves and chirping birds can produce positive psychological effects like stress reduction.

City planners need to factor in health benefits of green spaces and ensure that trees are used as natural sound barriers.

The summer of 2021 saw catastrophic wildfires in Greece, Italy, Turkey and North America, a phenomenon that is becoming increasingly common as climate change accelerates.

Natural wildfires occur when three elements combine:
Ignition: heat from the sun or a lightning strike to ignite a fire.
Fuel: sufficient combustible material to feed the flames.
Weather::conditions such as temperature, wind and relative humidity can enable the fire to spread.

There are three types of wildfires:
Crown fires: these ascend from ground to tree crown and can spread through the forest canopy. The most intense and dangerous form of wildfire, they are common in Mediterranean-climate woodlands and boreal forests.
Surface fires: these burn through leaf litter, dead material and vegetation on the ground and are most common in woodlands and savannahs.
Ground fires: these burn decomposed organic subsurface layers of soil and usually do not produce visible flames. Difficult to fully suppress, they can smoulder over winter and may re-emerge in spring.

What damage do wildfires cause?

Wildfires cause huge damage to property and human life, as they emit vast amounts of atmospheric pollutants, such as black carbon, particulate matter, and greenhouse gases. Some of this soot may be transported long distances and deposited over remote landscapes, including glaciers. That can reduce the ability of the Earth’s surface to reflect sunlight, leading to warming.

Large and frequent wildfires in boreal and tropical forests may transform carbon sinks into sources of greenhouse gases.

More frequent and more intense wildfires can produce a long-term change in plant species composition and structure of forest ecosystems. Reburns may also become more common, potentially reducing post-fire regeneration. Depending on the original forest type, reburns could possibly result in a shift to non-forest vegetation.

What role does climate change play?

Climate change is increasing the risk of larger, more intense fires. Prolonged warm and dry weather reduces vegetation moisture, increasing the risk of fire ignition and spread. In contrast, unusually high rainfall increases plant growth that then serves as fuel in the next dry season.

Climate change is also causing more frequent lightning strikes, which is the predominant driver of wildfires in the boreal forests of North America and northern Siberia.

Fighting Back

Building the financial and technical capacity to properly manage wildfires is critical, especially in developing countries. In recent decades, there has been a growing recognition of the need for indigenous fire management in preventing larger, more destructive fires in savannah and grassland ecosystems.

In South America, for example, some countries have incorporated indigenous elements into their wildfire strategies. In 2014, Brazil launched an indigenous-community-led wildfire management programme in the Cerrado, which has reduced the area burned by wildfires by up to 57% and mitigated 36% of associated greenhouse gas emissions. More than 2,000 local, traditional and indigenous fire brigade members are being hired and trained annually.

What else can be done?

Adopting new tools and technologies:
Australia is an example of how emerging technologies can be leveraged to prevent wildfires. The Australian approach focuses on building resilience and capacity before disaster strikes. The country has developed long-range prediction capability for wildfire weather conditions. Climate change projections are provided to emergency management groups, including wildfire agencies and planners.

Globally, improvements in remote sensing capabilities – satellites, ground-based radar, lightning detection, and data handling – can help us better monitor and manage wildfires.

Much of phenology is dependent on temperature, which is why phenological shifts over the past decades are among the most visible consequences of climate change. Phenological mismatches are altering a range of life cycle events, including migration, reproduction, hibernation, flowering, larval development and growth rates.

As our planet warms, phenological changes are occurring faster in marine environments than terrestrial ecosystems, which impacts various species. Migratory patterns of Atlantic salmon and brown trout are temperature dependent. Different phenological responses to climate change between freshwater and terrestrial ecosystems could affect animals who are dependent on both ecosystems such as many insects, amphibians or birds. This could cause disruption in their food webs and, ultimately, biodiversity loss.

Other birds, like the common murres (Uria aalge), need to precisely time their reproduction to the inshore migration of their main prey, small forage fish.

Mammals like caribou also face challenges when spring births no longer coincide with their peak food supply.

What can be done?

Conservation and ecosystem management measures could be taken to encourage micro-evolution, where species evolve to the new conditions.

Creating wildlife corridors enhances habitat connectivity and biodiversity, which can help with the near-term survival of these species. The more genetic diversity a species has, the greater the chance it can successfully adapt to the changing climate.

Still, the most meaningful way to curb phenological mismatches is by rapidly reducing CO2 emissions and thus mitigating the impact of climate change on ecological systems and global biodiversity.