brentl – Geobites

September 2, 2022September 2, 2022

We’re Here Because We’re Here Because… of Chance?

A painting of many stars as in a night sky, surrounded by planets, with their orbits drawn out.

Featured image: An artist’s depiction of many, many possible planets. This image was created by the European Southern Observatory (ESO).

Paper: Tyrrell, T. Chance played a role in determining whether Earth stayed habitable. Commun Earth Environ 1, 61 (2020). https://doi.org/10.1038/s43247-020-00057-8

Have you ever stayed up at night and wondered, why am I here? Or, more broadly, why are we here, including all living things on this Earth? Don’t worry, you’re not alone, and scientists like Professor Toby Tyrrell of the University of Southampton (UK) have been trying to answer these questions using the scientific method.

His conclusion? It may have just been the luck of the draw. After all, if we weren’t here in the first place, we couldn’t wonder why we were. (Scientists call this the weak anthropic principle.)

Climate scientists often describe their models as alternate (climate) histories. Tyrrell’s 2020 paper takes this idea to its ultimate conclusion, running 100 alternate climate histories on 100,000 randomly generated planets within the habitable zone of their randomly generated stars for 3 billion years. The question he’s trying to help answer is this: how likely was it that the Earth’s climate stayed habitable for the 4 billion years between the evolution of the first prokaryotic cells and us? Was it due to some intrinsic properties of planet Earth, or of life, or was it merely chance?

August 25, 2022August 31, 2022

One Sailors’ Legend Down, Many More To Go – Multiple Milky Sea Events Detected by Satellite

Processed satellite images showing a milky sea event in Java, 2019.

Featured image: Processed satellite images showing a milky sea event and its components in Java, 2019. From Miller et al, 2021 (figure 5).

Paper: Miller, S.D., Haddock, S.H.D., Straka, W.C. et al. Honing in on bioluminescent milky seas from space. Sci Rep 11, 15443 (2021). https://doi.org/10.1038/s41598-021-94823-z

Sailors see a lot of, well, stuff while they’re far from land. And they’re known for telling unbelievable tales, some of which later turn out to be more or less true. Milky seas are one of those: a horizon-to-horizon sea that glows white like the snow in the moonlight. In a 2021 paper, Dr. Steven Miller of Colorado State University and colleagues used satellites to look for these systems in hopes of understanding how and why these glowing patches form.

The first satellite detection of a milky sea event was also the work of Dr. Miller, in a 2005 paper that detected just a single event by combing ships’ logs and satellite archives from the preceding decade. Now, Miller’s research team has refined the algorithm that he’d previously developed for modern satellite records. Today’s satellite technology is better able to ‘see’ these events due to higher resolution of their images and can pick out the bioluminescent glow of microbes in the ocean better than the last generation of satellites.

November 4, 2021November 16, 2021

The Charney Report vs IPCC6: What’s changed in climate science in the last 40 years?

NASA satellite image of Earth from space, showing California wildfire smoke visible in the atmosphere.

Papers: Carbon Dioxide and Climate, a Scientific Assessment by Charney et. al (1979);
Climate Change 2021: The Physical Science Basis by the IPCC (2021)

Right now in Glasgow, Scotland, representatives of world governments and other parties are currently gathering yet again to negotiate political solutions to climate change at COP26. This is the 26th semi-annual Conference of the Parties on climate change, but the history of our understanding of the problem — and attempts to deal with it — goes back even further than that. Speaking strictly of the science of global warming and its effects, what do we know now that the participants of the first COP did not?