Roundup: Scientists urge more efforts in carbon emission reduction

Researchers from various countries have urged governments to focus more on mitigating carbon emissions, which they believe is more essential in the process of tackling climate change.

Researchers from esteemed academic institutions in the United States, Switzerland, Britain, and many more have voiced their concerns about climate change in a series of articles published Monday online in academic journals.

Negotiators convened at the ongoing UN climate change conference in Paris, also known as COP21, are eyeing an emissions path that will limit the rise in global temperatures to less than two degrees above pre-industrial levels.

In an article published in Nature Geoscience, researcher Reto Knutti and colleagues present a critique of the two-degree climate target and argue that attention should turn to mitigating dangerous emissions instead of debating particular temperature objectives.

Irrespective of the temperature target, evidence suggests that the rapid rise in global carbon dioxide emissions from industry and fossil fuel burning since 2000 has slowed markedly, or even reversed, in the past two years. This comes despite continuing economic growth, according to data presented in a commentary article in Nature Climate Change by another team of researchers.

This decoupling of emissions from economic growth could stem from some emerging and established economies moving away from using coal and towards using renewable energy sources, which suggests that this emissions trend might continue, the team say.

However, uncertainties in emissions over the coming decades make it difficult to determine if the peak in annual global emissions has yet been reached, according to the team.

As for approaches to tackling climate change, relying on technologies that remove greenhouse gases from the atmosphere, known as negative emissions technologies (NETs), to play a major role in the mitigation of these emissions is a high-risk strategy, according to a review in Nature Climate Change.

Pete Smith and colleagues, the authors of the review, assess the potential risks and opportunities of different NETs, and suggest that aiming to aggressively reduce emissions as soon as possible remains the safest strategy.

In realizing that strategy, some researchers argue that climate change litigation may have a role to play.

In a commentary in Nature Geoscience, James Thornton and Howard Covington outline an approach based on past relevant legal cases that could, in the future, lead to court orders to restrict greenhouse gas emissions from significant contributors to climate change.

In another commentary in Nature Geoscience, Katharine Ricke and colleagues argue that ambitious and early climate change mitigation is key, particularly for sectors where the impact of climate change increases rapidly at relatively low levels of warming, but then slows or levels off as temperatures continue to rise. Endit