Note: Concerns about climate issues stem from their essential role as matters of ecological science and management. The core challenge of climatology involves understanding and regulating the relationship between humans and their environment to avoid adverse impacts and to enhance beneficial ones. Because climate change leads to significant disruptions—such as habitat destruction, changes in species distribution, worsening droughts, flooding, and threats to human health—addressing these problems requires a scientific approach focused on the objective management of ecological systems. Employing ecological science ensures that solutions target the root causes and impacts of climate change, rather than being driven by ideological or political interests. Scientific management enables societies to plan for adaptation, support ecosystem health, and minimize negative outcomes for both nature and humanity. This approach promotes the effective stewardship of resources and the resilience of living systems, benefitting current and future generations.
Post from Steven E. Koonin below.
IMPACTS
Projections of the impacts of future climate changes
rely on assumptions about future greenhouse gas emis
sions fed into large computer models of the ocean and
atmosphere. Although those models can give a hazy
picture of what lies before us at the global scale, their
deficiencies on smaller scales are legion. For example,
two senior climate researchers firmly within the scie tific
mainstream have said this:
For many key applications that require
regional climate model output or for
assessingvlarge-scale changes from
small-scale processes, we believe that the
current generation of models is not fit for
purpose.1
That’s particularly important because adaptation
measures depend upon regional modelprojections. One
of the same senior researchers noted the following:
It is difficult, and in many places impossi
ble, to scientifically advise societal efforts to adapt in the face of unavoidable warming.
Our knowledge gaps are frightful because
they make it impossible to assess the
extent to which a given degree of warm
ing poses existential threats.2
Users of the model output similarly caution about being
overly credulous:
The use of these [climate] models to
guide local, practical adaptation actions is
unwarranted. Climate models are unable
to represent future conditions at the
degree of spatial, temporal, and proba
bilistic precision with which projections
are often provided, which gives a false
impression of confidence to users of
climate change information.3
Even if we can’t rely on unvalidated climate models,
we can get some sense of how the world has fared under
a changing climate by looking back to 1900. Since that
time, the globe warmed 1.3°C, about as much as the Inter
governmental Panel on Climate Change (IPCC) predicts
will occur in the next century under moderate future emissions. But even as the globe warmed and the popu
lation quintupled, humanity prospered as never before.
For example, global average lifespan went from thir
ty-two years to seventy-two years, economic activity per
capita grew by a factor of seven, and the death rate from
extreme weather events plummeted by a factor of fifty!
Any assertion that a similar warming over the next century
will be catastrophic is implausible and finds little support
in either IPCC science assessments or the underlying
scientific literature and data.
Although climate varies a lot on its own, many still
allege that we’ve broken the climate in the past few
decades. Yet table 12.12 of the most recent IPCC report
(AR6 WG1) shows it’s hard to find long-term global trends
in most types of extreme weather events, including
storms, droughts, and floods. And economic loss rates
have declined slightly over the past thirty years, averag
ing about 0.2 percent of global GDP.4 A wealthier world is
a more resilient world. Perhaps future climates will be a lot
worse. But the United Nations (UN) projects substantial
economic growth, even for an emissions-heavy future.
The IPCC’s 2014 Fifth Assessment Report said the follow
ing in chapter 10:
For most economic sectors, the impact
of climate change will be small relative
to the impacts of other drivers (medium
evidence, high agreement). Changes
in population, age, income, technol
ogy, relative prices, lifestyle, regulation,
governance, and many other aspects of
socioeconomic development will have
an impact on the supply and demand of
economic goods and services that is large
relative to the impact of climate change.5
Subsequent research has confirmed that warming
is expected to be a minor hinderance to growth—a few
degrees of warming by the end of the century would
make the growing economy a few percent smaller than it
might have been.6 For example, if the US economy were
to grow at an average annual rate of 2 percent, it would
be four times larger seventy years from now. A climate
impact of, say, 4 percent would reduce the growth from
400 percent to 384 percent, a change much smaller than
our ability to project that quantity. Of course, there are
uncertainties in these projections, GDP is not the only
measure of well-being, and the rich will fare better than
the poor. But the term “existential crisis” is hardly justified.7
6 FACTUAL CONTEXT
Another form of “climate impact” is the disruption
caused by large and rapid reductions in greenhouse gas
emissions. William Nordhaus’s work showed that there is
an optimal pace to reduce emissions: moving too quickly
causes turmoil and deploys immature technologies. His
2018 Nobel lecture stated that an economically optimal
decarbonization could let the global temperature rise in
2100 exceed 6°C (quadruple the Paris Accord guardrail
of 1.5°C!). Of course, that’s based on assumptions that
can be, and have been, challenged, but Nordhaus’s main
takeaway is “don’t panic”—take the time to reduce emis
sions gracefully.8
Read more here.