Benefits (conservative estimates):

• 10% improvement in policy decisions
• Applied to city budgets ($100M-1B+)
• Yearly benefit: $10M-100M per city
• Net Present Value (30 years, 5% discount rate): $150M-1.5B per city

I upvoted because I think you're touching on some interesting ideas. But I think you have a lot to do to demonstrate the scale of benefits you describe - if you have a more detailed analysis, I'd encourage you to link to it in the above section.

In particular: 

• What evidence there is for (at least) a 10% improvement in policy decisions? I can see how the process would be a substantial improvement over a 'pure democracy' (as you describe). But what you describe sounds very similar to what policy-focused civil servants should already be doing (at least in the UK, for national policy), in terms of assessing evidence and listening to various experts and advocates. Perhaps there is a gap at city-level?
• You appear to have taken the '10% improvement', and then multiplied it by the annual city budget in order to get the yearly benefit, and then multiplied this by 30 (with a 5% discount rate) to get the benefit over 30 years. This makes sense if '10% improvement' literally means 10% improvement in outcomes (rather than 'reallocating 10% of the budget').
  • But if this does mean 10% improvement in outcomes, it seems extremely implausible to me that such improvements can reoccur year-on-year. If a city's budget is horribly misallocated at the start, then there could be substantial improvements in the first few years - but you'll pretty quickly get to the point where there are relatively minor differences in the marginal cost-effectiveness of different activities.
    • [edit: I think this is wrong - a specific 10% improvement made in year 1 could of course reoccur in subsequent years. But there is an assumption that this 10% improvement wouldn't have been made at any other time without Election by Jury]
      • Could you provide some real (or even theoretical) examples to support your claims?
• You also mention x-risk. But even if what you are proposing is successful, I imagine it would take at least several decades to become widespread. Given the costs you indicate per city, I imagine it would be easier and much faster to try to influence existing politicians and civil servants?

I expect that the best thing to do will vary substantially depending on whether we're considering 

• (a) the EA community / movement-building per se
• (b) EA-aligned organisations trying to implement specific projects for a given cause area
• (c) fundraising

With (a), we'd want to consider some of the cultural risks or unintended consequences (e.g. as pointed by David Mathers and titotal) alongside the benefit of different perspectives. But this is less important for (b), where engaging and collaborating with people with more conversative perspectives could be critical for a project to succeed. With (c) I guess we should welcome and encourage funding from most sources, at least from small/medium donors (with larger donors we may want to be more cautious in case of reputational risks - but this obviously doesn't just apply to conservatives!)

Strong upvote for bothering to read the terms and conditions!

"You say that viewed from your and many EA’s moral framework, nature has no value?"

No - Gemma said nature has no "intrinsic moral value". There is a difference between intrinsic value and instrumental value. Intrinsic value is something that is valued for its own sake. Instrumental value is where something is valuable because it contributes to something else. 

Nature clearly has instrumental value, i.e. "we care about environmental protection primarily because of its impact on sentient beings".

But nature isn't the only thing that has an impact on sentient beings. The question is how we should best use additional resources (e.g. time and money) to improve outcomes for sentient beings.

Spending more on protecting nature is obviously one option, but not the only one. If we spend more on nature, we have less to spend on human disease and animal welfare etc. So we need to consider all the options, and focus on where we can do the most good.

That might be right. Another explanation is that even if she takes x-risk seriously, she thinks it's easier build political support around regulating AI by highlighting existing problems. 

I don't have a clear answer - but if your concern is intense suffering of animals, why not get involved with animal rights/welfare activism? Is there a reason to favour climate activism?

This is just speculation, but I wonder if it's more cost-effective to donate to a Senate candidate who is also running in a Presidential swing state? Maybe Pennsylvania, Michigan, Wisconsin, or Arizona?

It seems plausible that a strong Senate candidate could inspire voters to get out and vote for a President they're not enthusiastic about - essentially a 'reverse coattails' effect (though I don't think there's particularly strong evidence for this)

Also in the article "The Animal and Plant Health Agency - part of the Department for Environment, Food & Rural Affairs - gave the product the go-ahead."

I think there are a bunch of EAs working at Defra - I wonder if they helped facilitate this?

Lab-grown meat approved for pet food in the UK 

"The UK has become the first European country to approve putting lab-grown meat in pet food.

Regulators cleared the use of chicken cultivated from animal cells, which lab meat company Meatly is planning to sell to manufacturers.

The company says the first samples of its product will go on sale as early as this year, but it would only scale its production to reach industrial volumes in the next three years."

https://www.bbc.co.uk/news/articles/c19k0ky9v4yo

I have taken the pledge but I'm not currently donating 10%, so don't feel I can authentically promote it to others right now.