On the black side of the ledger, there has arguably never been a better time, as a
matter of probability, to be alive as a human. By many metrics, including infant
mortality, life expectancy, poverty reduction, dissemination of knowledge, and
declines in violence, the human condition has improved substantially over past
centuries (Pinker 2018). These gains have been facilitated by the astonishing pace
and success of scientific discovery and associated applications including the printing
press, engines, vaccines, antibiotics, pasteurization, batteries, electricity, transistors,
computers, refrigeration, steel, light bulbs, communications, combine harvester,
nitrogen fixation, birth control, molecular biology, and sequencing. Along with
other evidence-based solutions, such as sanitation, the green revolution, and disease
eradication programs, these efforts have likely saved billions of lives and improved
the lives of countless more. Of course, these observations about the human condition
are meant as broad strokes, and improvements are clearly not distributed evenly
within or among populations, with many critical issues requiring novel and more
equitable solutions.
On the red side of the ledger, anthropogenic global climate change (GCC) is set to
create unprecedented challenges for humanity and potentially escalate ongoing
losses of biodiversity to levels last observed during the biotic crisis 66 million
years ago. As many as one million animal and plant species are currently at risk of
extinction, with rates of loss expected to accelerate going forward (IPBES 2019).
Biodiversity declines, however, are difficult to gauge, in part, because only about
14% of the estimated 9 million extant eukaryote species are known to science. While
invertebrate animals represent roughly 80% of described species (and 95% of
estimated species), the conservation status of less than 1% is known (Collen et al.
2012). For groups that are better known, including terrestrial vertebrates, population
declines and range contractions have been substantial (Ceballos et al. 2020; Ceballos
et al. 2017). For example, nearly three billion birds have vanished since 1970 in the
United States and Canada (Rosenberg et al. 2019). Drivers of diversity declines
include habitat loss and fragmentation, pollution from pesticides and fertilizers,
overexploitation, and exotic species introductions; processes largely associated
with the intensification and globalization of agriculture. There is a tendency to
think that the consequences of GCC will increase gradually over time, but extreme
events have already caused the abrupt degradation of some ecosystems (Smale et al.
2019). Forecasting future biodiversity losses is even more challenging, owing to
uncertainties in how to model species interactions, evolution, dispersal, and other
key biological mechanisms (Urban et al. 2016). Nonetheless, climate-mediated
biodiversity declines have been predicted to occur in punctuated waves of die-offs
as ecological assemblages could collapse before 2030 in the oceans and begin by
2050 in terrestrial systems (Trisos et al. 2020).
Of course, the expansion of the human footprint and biodiversity declines are not
unrelated. Some of the forces, including market-based globalization, argued to foster
economic growth and reduce poverty in developing nations, also escalate systemic
risk to ecological systems. For instance, global commerce has been built on the back
of the combustion engine, together with the ability to extract large reservoirs of
carbon-based energy. This carbon was deposited over millions of years as buried
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K. M. Oliver and C. H. V. Higashi
matter of probability, to be alive as a human. By many metrics, including infant
mortality, life expectancy, poverty reduction, dissemination of knowledge, and
declines in violence, the human condition has improved substantially over past
centuries (Pinker 2018). These gains have been facilitated by the astonishing pace
and success of scientific discovery and associated applications including the printing
press, engines, vaccines, antibiotics, pasteurization, batteries, electricity, transistors,
computers, refrigeration, steel, light bulbs, communications, combine harvester,
nitrogen fixation, birth control, molecular biology, and sequencing. Along with
other evidence-based solutions, such as sanitation, the green revolution, and disease
eradication programs, these efforts have likely saved billions of lives and improved
the lives of countless more. Of course, these observations about the human condition
are meant as broad strokes, and improvements are clearly not distributed evenly
within or among populations, with many critical issues requiring novel and more
equitable solutions.
On the red side of the ledger, anthropogenic global climate change (GCC) is set to
create unprecedented challenges for humanity and potentially escalate ongoing
losses of biodiversity to levels last observed during the biotic crisis 66 million
years ago. As many as one million animal and plant species are currently at risk of
extinction, with rates of loss expected to accelerate going forward (IPBES 2019).
Biodiversity declines, however, are difficult to gauge, in part, because only about
14% of the estimated 9 million extant eukaryote species are known to science. While
invertebrate animals represent roughly 80% of described species (and 95% of
estimated species), the conservation status of less than 1% is known (Collen et al.
2012). For groups that are better known, including terrestrial vertebrates, population
declines and range contractions have been substantial (Ceballos et al. 2020; Ceballos
et al. 2017). For example, nearly three billion birds have vanished since 1970 in the
United States and Canada (Rosenberg et al. 2019). Drivers of diversity declines
include habitat loss and fragmentation, pollution from pesticides and fertilizers,
overexploitation, and exotic species introductions; processes largely associated
with the intensification and globalization of agriculture. There is a tendency to
think that the consequences of GCC will increase gradually over time, but extreme
events have already caused the abrupt degradation of some ecosystems (Smale et al.
2019). Forecasting future biodiversity losses is even more challenging, owing to
uncertainties in how to model species interactions, evolution, dispersal, and other
key biological mechanisms (Urban et al. 2016). Nonetheless, climate-mediated
biodiversity declines have been predicted to occur in punctuated waves of die-offs
as ecological assemblages could collapse before 2030 in the oceans and begin by
2050 in terrestrial systems (Trisos et al. 2020).
Of course, the expansion of the human footprint and biodiversity declines are not
unrelated. Some of the forces, including market-based globalization, argued to foster
economic growth and reduce poverty in developing nations, also escalate systemic
risk to ecological systems. For instance, global commerce has been built on the back
of the combustion engine, together with the ability to extract large reservoirs of
carbon-based energy. This carbon was deposited over millions of years as buried
264
K. M. Oliver and C. H. V. Higashi