Here is another very enjoyable conversation, with @Pandata19’s scientific advisory board member, Dr Jay Bhattacharya. Key ideas in this thread.

Here's more on the new mitigation scenario for 1.5C. How does it work? What would society look like? Are we willing to do what's required to stop climate breakdown? See thread.

1. Most models assume we need to keep growing the economy indefinitely. The problem is this makes it impossible to transition to zero emissions quickly enough; so they speculate on geoengineering and negative-emissions technologies to save us. Scientists reject this as too risky.

2. By contrast, this scenario proposes that high-income countries don't *need* more growth, and can scale down unnecessary production and consumption. This reduces energy demand (from 140 EJ in 2020 to 40 EJ in 2050), and enables a rapid transition to renewable energy.

3. What does it require? In the global North (Annex 1 countries)
•a shift from private cars to public transportation
•reduction in flights
•smaller average house size

Meanwhile, consumption in the global South (non-Annex 1 countries) rises to converge.

4. Significant reduction of aggregate material use. How? Longer product lifespans; regionalization of production and consumption; ban on advertising; a shift in taxes from labour to resources. All of this allows us to reduce ground freight, which cuts energy use.

https://t.co/odzm9VTdwZ

Thread for today. /0

It is fashionable for people to create sympathy to the unseen / unknown organisms. The poor things that can't stand up and fight for their own existence.

It makes for a brilliant narrative. It melts your hearts. And you get to play saviour of the oppressed by outraging. /1

But, for most part, such things are also false.

Amazon are the lungs of the world. Never mind that most of the world's oxygen production happens in open oceans. But these are harmless ones. Of course, we all love to maintain forests.

However, some things are sheer scare mongering.

For instance - take this: coral reefs will be permanently gone if mean / median temperatures raise by 1°C ..

But, really - how? Then you get a lecture on how CO2 will affect calcification.

Dig a bit deeper from another angle+

+ and you find that the earth was much much warmer during the age of Dinosaurs. So much so, that we had cold blooded lizards growing to sizes of buildings. Surely, there must have been tons of CO2 then!

And the ocean temps were quite high too.

Ct values can be used to estimate epidemic dynamics UPDATE! Ct values are expected to change depending on whether the epidemic is growing or declining, and we harness this to estimate the epidemic trajectory. Lots of cool new analyses and methods!

Highlights:
- Cts from symptom-based surveillance change over time, but the effect is weaker
- Methods to infer incidence using single cross-sections of Cts
- Unbiased by changing testing coverage
- Gaussian process (wiggly line) model for incidence tracking using Ct values
2/12

This work is *JOINTLY led* with @LeekShaffer and PI’d by @michaelmina_lab. Thank you also to the ever insightful @mlipsitch and to coauthors @SanjatKanjilal @gabriel_stacey and @nialljlennon. 3/12

Premise: times since infection depend on the epidemic trajectory. Distributions of randomly sampled viral loads proxy times since infection. With calibration, Ct values can estimate growth rate. We focus on qPCR in SARS-CoV-2, but the principle applies to any outbreak. 4/12

Result 1: viral loads are shifted higher (Cts lower) during epidemic growth and lower (Cts higher) during decline when individuals are sampled *based on the onset of symptoms*. We simulated linelist data under symptom-based surveillance and looked at TSI and Cts over time. 5/12