Happy new year!
I’ve decided once again to kick the new year off by listing my favorite 15 articles that I reviewed last year. I picked them for a mix of importance and being interesting, plus my
favorite two publications that I contributed to (Bradford et al. 2019, Fisher & Kareiva 2019). If you know someone who wants to sign up to receive these summaries, they can do so at
http://bit.ly/sciencejon
I also have gotten a great response from a webinar I hosted in December on how scientists can improve the impact of their research! If you weren't one of the almost 1,000 registrants, you can watch the webinar here:
https://www.openchannels.org/webinars/2019/improving-your-impact-guidelines-doing-science-influences-policy-and-management It's about 23 minutes of presentation followed by lots of Q&A and discussion, and you can also download the full paper the talk is based on from
http://bit.ly/strongerscience
Anderson et al. 2019
argues that while investing in natural climate solutions (aka NCS, e.g. trees)
is important to mitigate climate change, cuts to emissions from energy and
industry are also urgent and imperative. As they put it, it's not
"either/or" but "yes, and." Their key point is that while
NCS offer many benefits, delaying emissions reductions from energy and industry
by even a few years can add up to more than offset the reductions from NCS.
They close by calling for conservationists to ensure that NCS mitigation is
optimized, while also amplifying the need to work on complementary solutions to
reduce anthropogenic emissions at their source.
Bradford et al. 2019
is an opinion piece on soil carbon. The opening two lines sum it up well:
"Soil-based initiatives to mitigate climate change and restore soil
fertility both rely on rebuilding soil organic carbon. Controversy about the
role soils might play in climate change mitigation is, consequently,
undermining actions to restore soils for improved agricultural and
environmental outcomes." In other words, while scientists disagree a lot
about whether boosting soil carbon is useful for climate mitigation, we all
pretty much agree it's important for fertile and productive agricultural lands.
Read a bit more at
http://sciencejon.blogspot.com/2019/11/soil-carbon-what-is-it-good-for.html
or just read the paper (it's only 1,800
words).
Burivalova et al.
2019 is a literature review of how effective four strategies were in
delivering environmental, social, and economic outcomes. They looked at
creating protected areas (PAs), forest certification and reduced impact logging
(RIL), payment for ecosystem services, and community forest management. The
results are varied and complex but Figure 2 summarizes them very well - no
strategies always succeed, but all sometimes succeed (and note the caveat that
each square is not equivalent). PAs performed well environmentally (after
certification & RIL), but very poorly socially and economically. The
authors conclude that there are surprising gaps in the literature on monitoring
the efficacy of conservation strategies, and that before implementation local
evidence should be examined to minimize the chance of failure or even having a
strategy backfire.
Catalano et al. 2018
argues that conservation would do well to learn how to deal with failure from
other disciplines like medicine, business, and aviation. Specifically, we need
to recognize how much we can learn from failure (sometimes more than success),
rather than fearing it and avoiding tough measures as a result. They cover how
we learn from failure, why it's hard to constructively engage with it, how
understanding cognitive biases can help (see Table 1 for a great list to
consider), and the role of leaders in supporting efforts to identify and learn
from failure. The example of "no rank" military aviation debriefs is
interesting - they promote a culture with sharing useful feedack at its core.
My main take-away is that dealing with failure is not only key, but it's hard
and requires careful thought to do well.
The U.N.'s Intergovernmental Science-Policy Platform on
Biodiversity and Ecosystem Services (IPBES) released a summary of a major
report in May describing global biodiversity loss and extinctions (
Diaz et al. 2019). The short version is
"nature is in trouble, and so are we as a result." The most reported
estimate is that about 1 million species face extinction (many within decades)
unless we act to prevent that. I'd recommend looking at the policy summary and
at least reading the bold headlines to get a bit more of the key findings. A
few others worth highlighting include: declines in crop and livestock diversity
is undermining agricultural resilience, drivers of change in nature (e.g. land
use, direct exploitation, climate change, pollution, and invasives) are
accelerating, goals like the Aichi Biodiversity Target and the 2030 Agenda for
Sustainable Development cannot be met without major transformative changes
(changes which are possible, albeit challenging), the parts of the world where
declining nature is expected to hit people the hardest tend to be poor and/or
indigenous communities, international cooperation to build a more sustainable
global economy will be key to solve this problem, addressing the sustainability
of food will also be important, and land-based climate solutions (e.g.
bioenergy plantations and afforestation) have some tradeoffs. Many of these are
obvious; the summaries under each headline often include useful detail, but
there's too much to summarize at this level. So skim through and dive into the
topics that pique your interest. Download the whole report from
https://ipbes.net/global-assessment
Grill et al. 2019
estimates only about a third of the world's longest rivers (<1,000 km) are
freely flowing (defined here with a new metric that means neither dammed, nor
significantly impacted by water consumption or infrastructure in riparian areas
and floodplains). Those long free rivers are mostly in remote parts of the
Amazon, Arctic, and Congo. On the other hand, shorter river reaches are doing
better: 56% of long rivers (500-1000km) are freely flowing, rising to 80% and
97% for medium (100-500km) and short (10-100km) rivers respectively. However,
since they rely on global dam databases, they caution that they likely
overestimate freely flowing rivers due to missing data on small dams. The
figures (and table 1) have great details on how well connected each river reach
is, what limits connectivity most (96% one of the impacts of dams:
fragmentation, flow regulation, and sediment trapping), and connectivity broken
down by river length.
Kennedy et al. 2019 calculates
how modified by human activities land around the world is. While only 5% of
land area was 'unmodified', most of the world was 'moderately modified.' The
authors argue that ecoregions with moderate modification may be good candidates
for high priority conservation action, because they tend to have some
relatively intact lands near to highly modified lands (which thus may pose a
threat in the near future). In particular, the tropical and subtropical dry
broadleaf forests biome (mostly in Mexico, India, Argentina, & SE Asia) was
found to be the most threatened (high conversion relative to protection). While
they didn't include all threats (e.g. logging, invasive species, climate
change, and more) these data can be used to evaluate the suitability of lands
for protection. You can explore the findings and maps at
http://gdra-tnc.org/current/ and you
can download the data from
http://s3.amazonaws.com/DevByDesign-Web/Apps/gHM/index.html
Li et al. 2015
compares the net impact of different kinds of forests on local weather,
considering albedo and evapotranspiration. Their key finding is that
"tropical forests have a strong cooling effect throughout the year; temperate
forests show moderate cooling in summer and moderate warming in winter with net
cooling annually; and boreal forests have strong warming in winter and moderate
cooling in summer with net warming annually." This means that the net
climatic effect (accounting for carbon sequestration as well as local weather)
of tropical forests (and to a lesser extent, temperate forests) is stronger
than indicated by carbon alone, while for boreal forests the carbon benefit is
significantly offset.
Minx et al. 2018
is an overview from a 3-part series on negative emissions (which they define as
reforestation, soil carbon, biochar, BECCS, DACCS, enhanced weathering &
ocean alkalinization, and ocean fertilization). Table 2 summarizes potential
impact and costs from various studies, and Fig 6 has a great visual synthesis
of these data. They find afforestation, reforestation, and soil carbon as ready
for large-scale deployment (albeit reversible), and all but ocean fertilization
as having potential to deliver benefits by 2050. There are lots of other good
insights here and it's worth reading.
Two new lidar satellites were launched recently: ICESat-2
launched in Sep 2018 and GEDI in Dec (initial GEDI data should be released in
June, ICESat-2 hasn't announced a date yet). While GEDI is more focused on
measuring forest canopy height, ICESat-2 is also mapping vegetation (in
addition to ice sheets, clouds, land surface, and more). GEDI will focus on
middle latitudes, and ICESat-2 on the poles. Having these data available
globally will be a big deal, especially for estimating forest carbon. For more
on ICESat-2, Neuenschwander and Pitts
2019 has details on one of the planned data products (ATL08) which maps
both ground surface and tree canopies. It's a dense paper, but Figures 4 &
8 are useful to get a sense of the output (they used simulated data), and the
discussion has several useful details. The raw data is grouped into 100m cells
to have enough photons per cell, but another data product (ATL03) maps each
photon individually and can be used to investigate patterns within each 100m
cell. Note that tree canopy height is consistently underestimated by ATL08.
Soil organic carbon (SOC) is often claimed to improve crop
yields. Oldfield et al. 2019 tests that claim with a global meta-analysis
of maize and wheat. They find higher SOC is associated with higher yields, up
to ~2% SOC. They then look at the ~2/3 of global maize and wheat lands below 2%
to estimate the opportunity to improve yield by boosting those soils to 2% SOC.
Globally they estimate that we could produce ~5% more maize and ~10% more
wheat, which represents 32% of the global yield gap for maize (largely in the
US), and 60% for wheat (largely in China). Check out Figure 4 for global
opportunity maps. Note that there is a lot of variance in the data, and it's
even possible yields could decline slightly as SOC increases.
Pohl et al. 2017
is a cool but unusual science paper. The authors provide clear instructions in
10 steps for researchers to improve their impact (similar to the concepts in
Enquist et al. 2017 but aimed at implementation). Table 1 has a great summary
of the process - at a high level they recommend matching research questions to
knowledge needed to inform action, thinking about who to involve (e.g.
stakeholders) throughout the research process, and reflecting on lessons
learned. The authors have walked a variety of researchers through these 10
steps in a single day. Steps 5-9 provide helpful tips on how to identify a body
of stakeholders, and figure out how to break them down into who to co-produce
knowledge with, who to consult with, and who to simply inform. It seems like a
great framework to get scientists started, although it's a bit ironic to have
scientists think on their own about how to better incorporate input and
perspectives from stakeholders.
Sanchez-Bayo &
Wyckhuys 2019 looks across 73 studies of insect decline from cross the
world, and look at the drivers and other commonalities. A key limit of the
paper is that they excluded any study that did NOT show a chance in abundance
or diversity, so its utility is limited to explaining declines where they have
happened (see section 4.1) as opposed to quantifying how insect populations are
changing overall. The take-away is that habitat loss seems to be the primary
driver (~50% of declines), followed by 'pollution' (~26%, mostly pesticides and
fertilizer), then disease and invasive species (18%) and climate change (7%).
That means a sole focus on pesticides will miss key drivers of the problem.
Figure 3 has a breakdown by taxonomic order, highlighting that dung beetles are
in real trouble.
Photosynthesis in plants relies on an enzyme called RuBisCO,
sometimes called 'the most incompetent enzyme in the world' due to its
inefficiency and energy loss during respiration.
South et al. 2019 present a new transgenic GMO tobacco plant which
improves the efficiency of respiration. As a result, their best modified
tobacco plants had 41% higher biomass (including 33% more leaf biomass but also
larger stems). It's not clear how much of the biomass gain could be translated
to improved yields for grains or other crops, but that's still a potentially
huge step forward which should be further explored. Eisenhut & Weber 2019
is a nice very short (1.5 page) summary of the article, and you can also read a
blog about it here which includes some nice diagrams:
https://phys.org/news/2019-01-scientists-shortcut-photosynthetic-glitch-boost.html
REFERENCES:
Anderson, C. M., DeFries, R. S., Litterman, R., Matson, P.
A., Nepstad, D. C., Pacala, S., … Field, C. B. (2019). Natural climate
solutions are not enough. Science, 363(6430), 933–934.
https://doi.org/10.1126/science.aaw2741
Bradford MA, Carey CJ, Atwood L, Bossio D, Fenichel EP,
Gennet S, Fargione J, Fisher JRB, Fuller E, Kane DA, Lehmann J, Oldfield EE,
Ordway EM, Rudek J, Sanderman J, Wood SA. 2019. Soil carbon science for policy
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Burivalova, Z., Allnutt, T., Rademacher, D., Schlemm, A.,
Wilcove, D. S., & Butler, R. A. (2019). What works in tropical forest
conservation, and what does not: Effectiveness of four strategies in terms of
environmental, social, and economic outcomes. Conservation Science and
Practice, in press(March), 1–15.
https://doi.org/10.1111/csp2.28
Díaz, S., Settele, J., Brondízio, E., Ngo, H. T., Guèze, M.,
Agard, J., … Zayes, C. (2019). Summary for policymakers of the global
assessment report on biodiversity and ecosystem services-unedited advance
version. Retrieved from
https://www.ipbes.net/news/ipbes-global-assessment-summary-policymakers-pdf
and
https://ipbes.net/global-assessment
Grill, G., Lehner, B., Thieme, M., Geenen, B., Tickner, D.,
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Kennedy, C. M., Oakleaf, J. R., Theobald, D. M.,
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