Links: Early Life, Critical Minerals, Net Zero Emissions

Some interesting readings over the past couple of weeks.

1) In a Fierce Desert, Microbe ‘Crusts’ Show How Life Tamed the Land. Zack Savitsky describes a fascinating research program underway to study microbial life in the fierce Atacama Desert in Chile. These organic communities are called 'grit crust'. They coat pebbles and large sand grains on the desert floor. A closer examination has showed that they are composed of hundreds of species of cyanobacteria, algae, fungi, along with lichen combinations. These microbes play an important role in the biogeochemical fixation and cycling of elements and over millennia break down rock and enrich the soil in nutrients. They also give scientists a glimpse on how life may have first colonized land, perhaps as early as the Archean. 

2) Digging into India’s critical minerals dash. Recently, the Indian Ministry of Mines released the Critical Minerals for India report. India has also approved commercial mining for minerals containing the following elements —lithium, beryllium, titanium, niobium, tantalum and zirconium. These elements are raw materials for magnets used in wind turbines and EV motors. M Rajshekhar writes about the geological distribution of these elements and global supply chains, pointing out the challenges India faces in procuring a reliable supply of these materials necessary for its energy transition away from fossil fuels. 

3) Explainer: Will global warming ‘stop’ as soon as net-zero emissions are reached? Even if we stop emitting CO2 today, we are locked into hundreds of years of warming because of past emissions. I too have uttered these words, but it turns out that I, and many others, have been conflating two separate scenarios: constant concentrations versus zero emissions. Zeke Hausfather clarifies what these two different situations mean and how they will differently impact CO2 levels and future warming. 

Net zero CO2 scenario will very quickly stabilize temperatures or even slightly cool the earth, but that will also depend on emissions of  other confounding variables like aerosols and other greenhouse gases. Aerosols by blocking sun's energy have a cooling effect. On the other hand, achieving net zero too far in the future might still result in warming due to the feedback effects of other greenhouse gases like methane and nitrous oxide. Good explainer!