More than half of the warming effect from human-caused emissions is due to carbon dioxide (CO2). CO2 lingers in the atmosphere for hundreds of years, generating a continuous climate impact that would sustain present warming levels even if new emissions stopped. As a result, everyone knows that reducing CO2 is essential; however, it won't be enough to reverse or delay climate change in the coming decades.
Due to the urgency of our impending climate disaster, swift mitigation strategies that deliver greater short-term benefits than CO2 reductions alone are gaining favor. These solutions include reducing short-lived climate pollutants (SLCPs), which are responsible for almost half of global warming but have atmospheric lives of less than 20 years. This article will outline the part each of the four major SLCPs plays in the global warming puzzle.
Gauging The Impact
The traditional measures of climate impact do not work well for SLCPs. Generally, greenhouse gases (GHGs) are compared by their global warming potential (GWP). For example, in typical GHG accounting, one ton of methane equals 25 tons of CO2. But this measure assumes a 100-year timeframe. Because methane only lasts 12 years, the impact ratio is much higher, assuming a shorter time - after 20 years, one ton of methane has the warming effect of 72 tons of CO2.
Radiative forcing is the best metric for focusing on the short-term effects of each pollutant. This estimates Earth's energy budget change based on a GHG or particulate's total atmospheric concentration. For instance, CO2's radiative forcing is 1.66 watts per square meter, whereas methane is 0.48 W/m2. In other words, the methane in the atmosphere contributes the same warming effect as 29% of the warming from CO2. But, of course, there is significantly less methane in the air than CO2.
Methane
As mentioned above, methane (CH4) has a 12-year atmospheric lifespan but tremendous warming potential – equal to almost 30% of the radiative force of CO2. In addition to its substantial warming effect, methane contributes to tropospheric ozone as it degrades, another SLCP. Due to the danger, methane is one of six gases addressed by the Kyoto Protocol, even though it utilizes 100-year GWPs and ignores short-term climatic benefits.
Oil and gas production emits the most methane, often escaping during drilling and pipeline transport. Coal mining, sewage, landfills, and agriculture also contribute to methane production. Fortunately, some methane emissions can be collected and used to produce heat and electricity.
Black Carbon
Also called soot, black carbon is a particulate matter (PM) that affects the atmosphere differently from GHGs. Particles stay suspended in the air until they settle, are washed away by rain, or contribute to cloud formation. Soot particles can stay in the air for two to three weeks.
Black carbon soot absorbs the sun's energy, trapping heat. Consequently, one ton of black carbon has a 100-year warming impact of 1,000-2,000 tons of CO2. However, as with methane, the effect is much higher over a shorter time frame. For example, one ton of black carbon may equal 4,000 tons of CO2 over 20 years.
Black carbon contributes to more than global warming. Emissions discolor snow, glaciers, and sea ice, speeding ice melt. The worldwide radiative of this mechanism is 0.1 W/m2, but it's considerably greater in the Arctic and Himalayas. Furthermore, black carbon contributes to indoor and outdoor air pollution, which causes more than 3 million deaths yearly.
Most black carbon comes from the incomplete burning of fossil fuels or biomass. Most 20th-century black carbon emissions came from the U.S. and Europe; however, these emissions have dropped in recent decades because of air quality and public health measures. Unfortunately, other regions' emissions are rising.
Hydrofluorocarbons (HFCs)
HFCs are used in refrigeration, aerosols, and insulation to replace ozone-depleting CFCs and HCFCs after the 1987 Montreal Protocol banned them. HFCs vary in lifespan and warming influence. They can have a 100-year GWP between 1,300 and 14,800, while their atmospheric lifespan can vary from 14 to 270 years.
On average, HFCs have a 15-year lifetime and radiate 0.012 W/m2 in the aggregate. While it's not significant compared to the 1.66 W/m2 of CO2, HFCs are the fastest-growing GHG emissions, anticipated to double within a decade. However, lower-GWP replacements, leakage fixes, and refrigerant reclamation initiatives may minimize HFC emissions as technology improves.
Tropospheric Ozone
Tropospheric ozone is not directly released but rather the result of the combination of other atmospheric pollutants, including methane, nitrogen oxides, carbon monoxide, and some organic compounds. Tropospheric ozone only lasts a few hours or days in the atmosphere but has a 0.35 W/m2 radiative force – equal to over 20% of the warming of all the CO2.
Tropospheric ozone can also influence evaporation, cloud formation, precipitation amounts, and wind patterns. It reduces agricultural production and harms ecosystems by reducing plants' capacity to absorb carbon. Since these consequences generally occur where the precursors are released, they affect the Northern Hemisphere disproportionally.
SLCPs Are Dangerous but Present an Excellent Opportunity to Slow Global Warming
Methane, black carbon, methane, HFCs, and tropospheric ozone, have short atmospheric lives but large warming consequences, especially in the Arctic and other sensitive areas. Unlike long-lasting CO2, SLCP decreases could swiftly minimize warming consequences. Paired with worldwide initiatives to cut CO2 emissions, SLCPs provide an excellent opportunity to delay climate change over the next few decades while simultaneously benefiting public health and food security.
Key Takeaways
Go Lean – Methane is a problem in the global food system. Adopting a diet rich in nutrients and low in animal products will reduce the demand for animal livestock, one of the main drivers of methane emissions.
No Wood Stove – They might be nice in the autumn and winter, but modern heating and lighting systems are much better for the environment than carbon-rich fossil fuels.
Compost – Nitrogen-based synthetic fertilizers are huge emitters, and they can also pollute the soil and water through runoff. Stay natural, and try to run an organic garden instead.
More than half of the warming effect from human-caused emissions is due to carbon dioxide (CO2). CO2 lingers in the atmosphere for hundreds of years, generating a continuous climate impact that would sustain present warming levels even if new emissions stopped. As a result, everyone knows that reducing CO2 is essential; however, it won't be enough to reverse or delay climate change in the coming decades.
Due to the urgency of our impending climate disaster, swift mitigation strategies that deliver greater short-term benefits than CO2 reductions alone are gaining favor. These solutions include reducing short-lived climate pollutants (SLCPs), which are responsible for almost half of global warming but have atmospheric lives of less than 20 years. This article will outline the part each of the four major SLCPs plays in the global warming puzzle.
More than half of the warming effect from human-caused emissions is due to carbon dioxide (CO2). CO2 lingers in the atmosphere for hundreds of years, generating a continuous climate impact that would sustain present warming levels even if new emissions stopped. As a result, everyone knows that reducing CO2 is essential; however, it won't be enough to reverse or delay climate change in the coming decades.
Due to the urgency of our impending climate disaster, swift mitigation strategies that deliver greater short-term benefits than CO2 reductions alone are gaining favor. These solutions include reducing short-lived climate pollutants (SLCPs), which are responsible for almost half of global warming but have atmospheric lives of less than 20 years. This article will outline the part each of the four major SLCPs plays in the global warming puzzle.
Gauging the Impact
The traditional measures of climate impact do not work well for SLCPs. Generally, greenhouse gases (GHGs) are compared by their global warming potential (GWP). For example, in typical GHG accounting, one ton of methane equals 25 tons of CO2. But this measure assumes a 100-year timeframe. Because methane only lasts 12 years, the impact ratio is much higher, assuming a shorter time - after 20 years, one ton of methane has the warming effect of 72 tons of CO2.
Radiative forcing is the best metric for focusing on the short-term effects of each pollutant. This estimates Earth's energy budget change based on a GHG or particulate's total atmospheric concentration. For instance, CO2's radiative forcing is 1.66 watts per square meter, whereas methane is 0.48 W/m2. In other words, the methane in the atmosphere contributes the same warming effect as 29% of the warming from CO2. But, of course, there is significantly less methane in the air than CO2.
Methane
As mentioned above, methane (CH4) has a 12-year atmospheric lifespan but tremendous warming potential – equal to almost 30% of the radiative force of CO2. In addition to its substantial warming effect, methane contributes to tropospheric ozone as it degrades, another SLCP. Due to the danger, methane is one of six gases addressed by the Kyoto Protocol, even though it utilizes 100-year GWPs and ignores short-term climatic benefits.
Oil and gas production emits the most methane, often escaping during drilling and pipeline transport. Coal mining, sewage, landfills, and agriculture also contribute to methane production. Fortunately, some methane emissions can be collected and used to produce heat and electricity.
Black Carbon
Also called soot, black carbon is a particulate matter (PM) that affects the atmosphere differently from GHGs. Particles stay suspended in the air until they settle, are washed away by rain, or contribute to cloud formation. Soot particles can stay in the air for two to three weeks.
Black carbon soot absorbs the sun's energy, trapping heat. Consequently, one ton of black carbon has a 100-year warming impact of 1,000-2,000 tons of CO2. However, as with methane, the effect is much higher over a shorter time frame. For example, one ton of black carbon may equal 4,000 tons of CO2 over 20 years.
Black carbon contributes to more than global warming. Emissions discolor snow, glaciers, and sea ice, speeding ice melt. The worldwide radiative of this mechanism is 0.1 W/m2, but it's considerably greater in the Arctic and Himalayas. Furthermore, black carbon contributes to indoor and outdoor air pollution, which causes more than 3 million deaths yearly.
Most black carbon comes from the incomplete burning of fossil fuels or biomass. Most 20th-century black carbon emissions came from the U.S. and Europe; however, these emissions have dropped in recent decades because of air quality and public health measures. Unfortunately, other regions' emissions are rising.
Hydrofluorocarbons (HFCs)
HFCs are used in refrigeration, aerosols, and insulation to replace ozone-depleting CFCs and HCFCs after the 1987 Montreal Protocol banned them. HFCs vary in lifespan and warming influence. They can have a 100-year GWP between 1,300 and 14,800, while their atmospheric lifespan can vary from 14 to 270 years.
On average, HFCs have a 15-year lifetime and radiate 0.012 W/m2 in the aggregate. While it's not significant compared to the 1.66 W/m2 of CO2, HFCs are the fastest-growing GHG emissions, anticipated to double within a decade. However, lower-GWP replacements, leakage fixes, and refrigerant reclamation initiatives may minimize HFC emissions as technology improves.
Tropospheric Ozone
Tropospheric ozone is not directly released but rather the result of the combination of other atmospheric pollutants, including methane, nitrogen oxides, carbon monoxide, and some organic compounds. Tropospheric ozone only lasts a few hours or days in the atmosphere but has a 0.35 W/m2 radiative force – equal to over 20% of the warming of all the CO2.
Tropospheric ozone can also influence evaporation, cloud formation, precipitation amounts, and wind patterns. It reduces agricultural production and harms ecosystems by reducing plants' capacity to absorb carbon. Since these consequences generally occur where the precursors are released, they affect the Northern Hemisphere disproportionally.
SLCPs Are Dangerous but Present an Excellent Opportunity to Slow Global Warming
Methane, black carbon, methane, HFCs, and tropospheric ozone, have short atmospheric lives but large warming consequences, especially in the Arctic and other sensitive areas. Unlike long-lasting CO2, SLCP decreases could swiftly minimize warming consequences. Paired with worldwide initiatives to cut CO2 emissions, SLCPs provide an excellent opportunity to delay climate change over the next few decades while simultaneously benefiting public health and food security.
Key Takeaways
Go Lean – Methane is a problem in the global food system. Adopting a diet rich in nutrients and low in animal products will reduce the demand for animal livestock, one of the main drivers of methane emissions.
No Wood Stove – They might be nice in the autumn and winter, but modern heating and lighting systems are much better for the environment than carbon-rich fossil fuels.
Compost – Nitrogen-based synthetic fertilizers are huge emitters, and they can also pollute the soil and water through runoff. Stay natural, and try to run an organic garden instead.
