Monday, April 3, 2023

April 2023 science summary



In case you missed it last month, check out the paper I co-authored on gender equity (I repeated the summary below, read or skim the whole paper if you have time, or at least read this blog overview).

The IPCC's latest synthesis report came out recently (and I have a short summary below), so the need to do more on climate change is on my mind.

Want to work on climate change via energy modernization at Pew? We're hiring for three jobs right now on a team that I'm super excited about. If you have any questions and/or may be interested please take a look at the posts and then let me know if you want to know more (and please pass them on):

  1. Senior Officer, Clean Grid and Energy

  2. Officer, State Campaigns

  3. Senior Associate, State Campaigns

Also - recently I am playing less w/ AI and reading more science myself, but thought this was a nice overview of strengths and weaknesses between ChatGPT, Bing, and Bard.

If you know someone who wants to sign up to receive these summaries, they can do so at (no need to email me).


The IPCC's latest report (the AR6 synthesis) recently became available (here’s a direct link to the 36 page summary for policy makers). If you've been following all the IPCC reports, there is no new info here. But there is a persistent thread of clarity that I found helpful. Of the many findings, the ones that stood out to me are:

  1. The planet has warmed 1.1 degrees C already (1.6C on land)

  2. The world is currently roughly on track for 3.2 C of warming based on implemented policies (Fig SPM5a, w/ range from 2.2C to 3.5C).

  3. Good news - that means that "business as usual" is a little worse than RCP4.5 (Intermediate Emissions), ranging from Working Group III scenarios C5 to C7 (C7=High GHG emissions or SSP3-7.0). The high emissions (RCP8.5) scenario is pretty unlikely since it would require emissions to go up substantially over what is predicted. See Table 1 in Box SPM.1 for details.

  4. Bad news - look more closely at Fig SPM5a. The paths to limit warming to 2C or 1.5C assume sharp cuts starting in 2020, which means even if we act immediately, cuts would have to be much sharper to make those pathways feasible (the report notes the lack of both commitments and financing). We should still make the attempt, but remember there is no magic binary threshold, and every bit of warming we avoid has real value.

  5. They project climate impacts on species loss, human health, and food production (see Figure SPM3).

I was struck by two quotes in particular:

“Adaptation options that are feasible and effective today [JF reminder - elsewhere they note: "‘today’ refers to 2019"] will become constrained and less effective with increasing global warming.”

“All global modelled pathways that limit warming to 1.5°C (>50%) with no or limited overshoot, and those that limit warming to 2°C (>67%), involve rapid and deep and, in most cases, immediate greenhouse gas emissions reductions in all sectors this decade.” (again, immediate relative to 2019).

The press release also notes that "Emissions should be decreasing by now [JF - again, that's 2019] and will need to be cut by almost half by 2030, if warming is to be limited to 1.5°C." This blog post highlights existing progress and what we need to do next.

AI side note: I asked Google Bard (their new beta AI) "What does the latest IPCC synthesis report say is the most likely amount of warming the world will experience?" and got a wrong answer: "The latest IPCC synthesis report says that the most likely amount of warming the world will experience is 1.5 degrees Celsius above pre-industrial levels.” (along with other text). But when I asked Bard "How much has the earth warmed so far, according to the latest IPCC synthesis report" it correctly states: "According to the latest IPCC synthesis report, the Earth has warmed by 1.1 degrees Celsius (2 degrees Fahrenheit) since the start of the industrial era."


Pearson et al. 2023 investigate whether restoring whale populations is likely to have a significant impact on climate mitigation. The idea being evaluated is that beyond carbon stored in whales themselves (which ends up in the deep sea when they die), that their poop stimulates a lot of phytoplankton growth which leads to net carbon capture (see Fig 1). The TL;DR results: whales and their poop MAY provide climate mitigation benefits but: we don't know yet, it'll take a long time to know, and additionality may be low (so don't sell whale carbon credits, please). See Box 1 for concerns w/ whale carbon credits, and box 2 for outstanding questions to be answered. They do note that whale recovery can be a "low regret" strategy, and I'd agree as long as it doesn't delay emissions reductions or otherwise pull resources from more proven climate solutions.


NatureServe's 2023 Biodiversity in Focus US report is a high level look at threatened species (imperiled or vulnerable) in the US. It's short and worth reading the whole thing. They find 34% of plant species and 40% of animal species are threatened, and 41% of the ~400 ecosystem groups in the US are at risk of "range-wide collapse" (meaning being replaced or substantially transformed). Figure 1 and 2 have breakdowns of averages for plants and animals by subgroups. For plants cacti are the worst off at 48% threatened and sedges are the least threatened at 14%. Freshwater snails are the most threatened animals (75%, and other FW groups are all more threatened than average) while birds are the least threatened (12%) and bees are about average (37%). Note that % of species that are threatened is different than looking at % of individual organisms or biomass that is threatened (all are useful metrics, Audubon's State of the Birds report looks at trends in bird population size). Figure 3 shows the most and least threatened ecosystems; unsurprisingly virtually all tropical ecosystems are threatened (they had relatively small extents originally, and are valuable for agriculture), while cliffs / rock and alpine and tundra ecosystems fare the best due to less threat of conversion to other land uses and higher rates of protection (Figure 5). They don't provide details but I would guess these are relatively short-term predictions, as climate change will threaten a lot of alpine and tundra ecosystems in the long term. Figure 4 shows how protected different species groups and ecosystems are. Almost 30% of vascular plant species are protected >50% of their range, but only 15% of vertebrate species are that protected. Finally, Figure 9b shows which states have the highest % of their area in at-risk ecosyetsms (NE, MT, and SD score the highest due to large at-risk grasslands), and Figure 11 shows priority areas for conserving imperiled species. With some exceptions (like FL) Figures 9 and 11 highlight different priority areas; Fig 11 focuses on relatively small and irreplaceable places that the most threatened species rely on, while Fig 9 focuses on more intact and lower diversity ecosystems that are at risk of being transformed (but with less potential for species extinctions). The authors conclude that the Restoring America's Wildlife Act (RAWA) guided by State Wildlife Action Plans (SWAPs) is our best bet to catalyze massive investment in conservation of the places that need it most.


Jewell et al. 2023 surveyed directors and board members in charge of state wildlife agencies in the SE U.S. about future conservation challenges and how they plan to respond. They found that the respondents were focused on funding and 'agency relevance' (including changing values and fewer hunters) but less concerned about climate change (see Table 2). One quote stuck out at me, which was that they saw climate change impacts as important at time-scales beyond decades, and thus not urgent to act on (they also saw it as too political). By comparison, they saw education and outreach as critical to recruit hunters and tell the public the value of hunting and fishing. Agency directors average 5 years in office, so short-term things they can do may be more appealing. The authors call for engaging decision makers around the science of how climate change is already affecting wildlife, how that is expected to shift over time, and what actions or preparations can be taken now to help.


Moore et al. 2023 is an interesting metanalysis of how vehicle collisions impact different wildlife populations around the world. Their 83 studies (of 150 populations of 69 species) are not representative / proportional of all wildlife. Most are of either even-toed ungulates (like elk and pigs) or carnivorans (like bear and big cats), roadkill studies inevitably concentrate on places where road mortality is significant, and a lot of the studies have really small samples. But they make a good case that it's a more important issue than is typically understood. Of the 58 studies that looked at roadkill as a % of all mortality over half found roadkill to be <15%, but 25 studies found 15-45% mortality from roadkill, 6 were 45-60%, and 3 were 60-80% (although they don't provide the data in a table, so I wonder if those 3 studies are weak / small N / outliers). They also found roadkill was the biggest source of mortality for 28% of populations studies, and it was in the top 3 for virtually all studies (again, likely a mix of it being an important threat AND a skewed study selection). Check out Figure 4A and 4B to see the biological orders hit hardest by roadkill (Tasmanian devils lost the most per year, opossums had the highest share of mortality from roads).

James et al. 2023 asked over 900 science & conservation staff of The Nature Conservancy about their careers and influence, and how they perceived their gender as impacting that. We found that women had less influence, experienced many barriers to their careers (including harassment, discrimination, and fear of retaliation for speaking out), and that men overestimated gender equity. Only have 5 minutes? Skip to the recommendations on page 7 (we ask orgs to: show public leadership on equity, improve transparency and accountability, diversify teams and improve career pathways for women, be flexible, include training and mentoring as part of broader change, help women connect, address sexual discrimination and harassment, and consider intersectionality). If you have 15 minutes more, read the quotes in Table 2 (p5-8) because they're really compelling and illustrative. Or if you're with the half of men and 3/4 of women in our sample who think we have more to do on gender equity (rather than that we've already "gone overboard" or that it's not an issue as some men reported), just read the whole damn paper because there's a lot of interesting detail and nuance in the results. I learned a ton while helping out on it, and I'm excited to start advocating for the recommendations. You can read it at: or a short blog at


IPCC (2023). AR6 Synthesis Report. (accessed Mar 24, 2023).

James, R., Fisher, J. R. B., Carlos-Grotjahn, C., Boylan, M. S., Dembereldash, B., Demissie, M. Z., Diaz De Villegas, C., Gibbs, B., Konia, R., Lyons, K., Possingham, H., Robinson, C. J., Tang, T., & Butt, N. (2023). Gender bias and inequity holds women back in their conservation careers. Frontiers in Environmental Science, 10(January), 1–16. or

Jewell, K., Peterson, M. N., Martin, M., Stevenson, K. T., Terando, A., & Teseneer, R. (2023). Conservation decision makers worry about relevancy and funding but not climate change. Wildlife Society Bulletin, November 2022, 1–14.

Moore, L. J. ., Petrovan, S. O., Bates, A. J., Hicks, H. L., Baker, P. J., Perkins, S. E., & Yarnell, R. W. (2023). Demographic effects of road mortality on mammalian populations: a systematic review. Biological Reviews, 3.

NatureServe. (2023). Biodiversity in Focus: United States Edition.

Pearson, H. C., Savoca, M. S., Costa, D. P., Lomas, M. W., Molina, R., Pershing, A. J., Smith, C. R., VillaseƱor-Derbez, J. C., Wing, S. R., & Roman, J. (2023). Whales in the carbon cycle: can recovery remove carbon dioxide? Trends in Ecology & Evolution, 38(3), 238–249.



p.s. The photo is of a dead copperhead I found on a road near Luray, VA