About half of global warming is driven by pollutants that aren’t carbon dioxide. There are several of these “super pollutants” — so named because of their outsized ability to increase global temperature even in very small amounts. They include methane, nitrous oxide, tropospheric (or near ground-level) ozone, black carbon and f-gasses.

Because CO2 can last in the atmosphere for thousands of years, we have rightly focused on mitigating and lowering those emissions. Yet because climate change has been driven by the buildup of CO2 over time, even stopping those emissions tomorrow won’t immediately slow warming. 
By contrast, most super pollutants last for days to maybe a decade. This is good news, as Ilissa Ocko, senior climate scientist at Climate Spark Solutions, explains: “The moment we stop replenishing the atmosphere with those emissions, we can almost immediately eliminate their warming impact on the climate.” 
Methane, for example, is about 80 times more potent a greenhouse gas than carbon dioxide, when the impact is averaged over 20 years. But it only stays in the atmosphere for roughly a decade. There are now multiple satellites tracking methane emissions and making their data available to the public, including MethaneSAT, led by the Environmental Defense Fund (EDF).

Millie Chu Baird of EDF says the idea is to help emitters know about their own contributions to atmospheric methane and to give more teeth to regulations of the gas.

“There's no more ability to just hide, deny, and keep reporting at this low level of estimates. It's like literally we'll be able to track how you're doing against these public commitments.  And so it has changed the tenor of the conversation,” she says.

Minimizing leaks from oil and gas production, which is what MethaneSAT is focused on, is an easier sell because there’s a profit incentive.

“The methane conversation with oil and gas companies is like, this is a waste product. It's commonly understood that with available technology, you can reduce your emissions by 75%. Sixty percent at no net cost because if you reduce the leaks, you can sell the product,” Baird says.

But reducing emissions of nitrous oxide, which largely comes from synthetic fertilizers used to grow half the world’s food, is a harder problem to solve.

“ It's always difficult from an environmental perspective to do policy in the agricultural sector because pollution there is much more diffuse,” says David Kanter, an associate professor of environmental studies at NYU. When it comes to the use of fertilizer, “there are many parts of the world [with] a huge amount of over-application, either because the fertilizer is subsidized or simply because maximizing yield is the absolute top priority.”

More precise methods of applying fertilizer or delayed-release formats could help with this. There’s even new technologies exploring using gene-edited microbes to fix nitrogen directly in the root zone of plants. And we do need to address the problem of excess in the nitrogen cycle because it leads to a series of cascading effects.

Because of the unique chemistry of the nitrogen cycle, it can go on a “journey of environmental destruction," Kanter says. “It can first make air pollution worse, it can then be transformed into nitrate and pollute water. So high nitrate levels are linked with increased risk of colon cancer, blue baby syndrome, algae blooms that lead to massive fish kills, and then that same atom of nitrogen that has been in air pollutant, and then a water pollutant can be transformed yet again to nitrous oxide, where it contributes to climate change and ozone depletion.” 
But the good news is “if we manage nitrogen better, you get a whole host of co-benefits and human health benefits as a result.” 

Note: Transcripts are generated using a combination of automated software and human transcribers and may contain errors. Please check the actual audio before quoting it.