8 Scientific American, December 2020LETTERS
[email protected]BIOMASS APPEAL
In “The Biomass Bottleneck,” Eric Toens-
meier and Dennis Garrity address the
strategy of drawing down billions of tons
of carbon dioxide by using biomass for en-
ergy and carbon capture. Their analysis
concludes that the amount of biomass re-
quired would leave the world with inade-
quate arable land to grow food. And they
indicate that available biomass waste that
currently has no other use is not available
in sufficient quantity to make a significant
dent in the climate change crisis.
I wish to call attention to a recent anal-
ysis by a consortium of scientists collabo-
rating with Lawrence Livermore National
Laboratory entitled Getting to Neutral: Op-
tions for Negative Carbon Emissions in Cal-
ifornia. The goal of this work was to create
a cost-effective plan to bring California to
carbon neutrality by 2045. In the report, the
biggest contributor to attaining this goal is
the conversion of waste biomass to fuels.
The CO 2 generated in producing such fuels
can then be sequestered underground, lead-
ing to a net removal of CO 2 from the atmo-
sphere without impacting food production.
I also wish to make the general point that
some fraction of the biomass that is cur-
rently used for certain applications, such as
animal feed, might need to be directed to
clean energy generation and carbon cap-
ture in a carbon-constrained future.
I wholeheartedly agree with the au-
thors that improvement in agricultural
practices is profoundly important. Solv-
ing the climate crisis will require many
different activities, whose nature can vary
with geographical location. Utilizing
waste biomass can play a significant role
in allowing California to achieve its goal
of carbon neutrality.
Joffre Baker Montara, Calif.Toensmeier and Garrity omit an impor-
tant variable in their discussion of the po-
tential for biomass energy. If people were
to adopt a plant-based diet, the amount of
agricultural land needed for food produc-
tion would be greatly reduced. When
crops are fed to animals, the loss of effi-
ciency is staggering. And cattle are a ma-
jor source of methane emissions. If peo-
ple ate less meat, much existing cropland
could be used for biomass energy with no
harm to human welfare.
M. Barton Laws Brown University
School of Public HealthLAST HUMAN STANDING
In “Survival of the Friendliest,” Brian Hare
and Vanessa Woods imply that a lack of
friendliness led to the extinctions of at least
four other known human species that were
mutually extant with our own. But there are
anthropologists who attribute our singular
success to pursuing the genocidal destruc-
tion of all the other competing species. Sim-
ilarly, many present-day religions claim su-
periority over all other competing religions,
often seeking to eliminate the competition.
Is there a genetic linkage between species
domination and religious domination?
Roy Bruno Redmond, Wash.The authors refer to our species succeed-
ing, but they never directly define what hu-
man success is, unless it is some crude Dar-
winian measure of reproduction and the
displacement of other species. We can look
around and see the impact of the “success”
of eight billion people: We have the capac-
ity for culture and can cooperate. Yet ourcooperation has been used to wage war and
commit genocide (even slaughtering peo-
ple halfway across the globe); to cause ex-
tinctions and greatly diminish the numbers
of other species; to turn complex ecosys-
tems into monocultures; and to wreck a
planet’s climate. We have lost the ability to
control the narcissists we produce. If this
is cultural prowess and success, let’s say
that the story is not over yet. And it does
not seem particularly friendly. There is
good evidence we have become less emo-
tionally mature as a species.
David Johns McMinnville, Ore.RACE AND COVID-
Thank you for “Black Health Matters,” by
the Editors [Science Agenda], as well as
the powerful imagery used to visually
highlight the discrepancy in health care as
it pertains to race. The illustration should
be hung in research institutions and poli-
cy-making rooms around the country.
I agree that many of the health care dis-
parities stem from systemic racism and pol-
icies, such as those that prevented Black
people, in particular, from purchasing Fed-
eral Housing Administration–insured mort-
gages in our country until 1968—forcing
many to live in segregated and overcrowd-
ed communities that have now become a
breeding ground for pandemic-related ill-
ness. As a result of these policies, neighbor-
hood schools became rife with underfund-
ed, poor-quality education. That problem,
in turn, led to the inability of many of those
neighborhoods’ residents to access higher
education or jobs with decent wages, and
they had far fewer opportunities to receive
adequate health insurance and health care.
The result was a reduced ability to learn
about such health impacts as vitamin D de-
ficiency, high blood pressure, and so on. Ad-
ditionally, previously redlined neighbor-
hoods have been surrounded by food des-
erts—with stores providing minimal access
to fresh fruits and vegetables and rampant
with an overabundance of processed andAugust 2020
“Solving the climate crisis will require
many different activities, whose nature
can vary with geographical location.”
joffre baker montara, calif.