How do we define climate change?
Climate change is the long-term change in the average weather patterns of
Earth’s local, regional, and global climates.
“For about the last ten thousand years, the Holocene period in geological
terms, humanity has occupied a fairly stable climate,” explains Miranda Massie
(GSAS M.A. ‘92), Director and Founder of
The Climate Museum.
“While there have been changes from time to time, they are slight
in the context of planetary history, and overall, weather systems have been
predictable and coastlines have remained in place. Those conditions of
relative stability are what allowed agriculture and then civilization to
flourish.
"In other words, the Holocene climate is a basic
precondition for what we understand about ourselves and our society. What we
are seeing now is the fundamental disruption of that stability.”
What are some of the main causes of climate change?
“The fundamental changes to the stability of our climate are primarily due to
the burning of fossil fuels like oil, coal, and natural gas, which started at
a mass scale during the Industrial Revolution,” Massie says.
Dan Esty, Hillhouse Professor of Environmental Law and Policy at the Yale
School of the Environment and Yale Law School, explains that when we burn
fossil fuels to do things like power our homes and vehicles and engage in most
agricultural and manufacturing processes, we emit greenhouse gases.
Often referred to as “GHGs”, these gases act like a heat-trapping
blanket over the planet and prevent the heat that comes from sunlight from
leaving the atmosphere. Some of the more common greenhouse gases are carbon
dioxide, methane, and chlorofluorocarbons, and all have different
heat-trapping capacities.
“In addition to emitting greenhouse gases, another contributor to climate
change is our destruction of carbon sinks, or places that would naturally
store this carbon for us and keep it out of the atmosphere,” Esty says.
“Plants and trees, for example, are natural carbon sinks. When we
have a forest that is cut or burned down, we lose a sink, and we therefore
lose some of the ability of the earth to absorb carbon dioxide. Widespread
deforestation and changes in land use patterns, therefore, are significant
drivers of the climate crisis.”
Massie also points out that while burning fossil fuels and eliminating carbon
sinks is the clear physical cause of the climate crisis, this fossil
fuel-based economy does not exist independently from our culture.
“The cultural and social context for the climate crisis is critical.
Inevitably, the burning of fossil fuels as our primary source of energy both
comes from and reinforces basic social understandings and practices developed
over time: how human beings have come to relate to the rest of the natural
world and to each other.
"At the heart of this lies a culture of
exploitation–the sense that the rest of nature exists, inexhaustibly, for
human use alone–and that some human beings similarly exist as resources for
others with more social power.
"Colonization, rigid racial
hierarchies, and the simultaneous fetishization and abuse of coal miners are
examples of exploitation and dehumanization in our history and culture.
"These dynamics are deeply bound up with the fossil fuel economy,”
Massie says. “Therefore, the entire organization of society and culture can
also be usefully understood as the cause of climate change.”
What evidence tells us that climate change is happening?
“There is copious and irrefutable evidence that climate change is happening,
but a lot of it is not immediately apparent to the average person,” Massie
says. “For example, the concentration of carbon dioxide and other heat
trapping gases in the atmosphere is not something that you and I can directly
perceive. It’s something that scientists have measured.”
Esty explains that there is an entire science dedicated to extrapolating and
tracking global temperatures and carbon dioxide levels across human history.
Scientists can reconstruct human history by carving out polar ice
cores or sediment from the ocean floor and examining their physical and
chemical makeup to understand how the environment has changed over centuries.
“As a result of this science, we know very clearly that the level of carbon
dioxide in the atmosphere has risen from a couple of 100 parts per million
(ppm) in pre-industrial times to over 400ppm now,” Esty says. “That is a
signal that we’ve dramatically increased the level of greenhouse gases in our
atmosphere.”
Massie adds the example of the oceans becoming more acidic as they absorb
higher levels of carbon dioxide, both of which can be measured by scientists
and further proven by things such as the bleaching of coral reefs.
However, for some communities around the world, climate change is already
quite tangible.
“In recent years, we have seen growing evidence of increased intensity of
windstorms, hurricanes, flooding, and more devastating forest fires,” Esty
says, giving examples from the last decade including Hurricane Sandy and the
Australian wildfires.
“We have also seen glaciers and ice sheets
crack and melt, causing measurable sea level rise. All of that gives us a
signal that we’ve got a real problem that needs to be addressed.”
What are the impacts of climate change, both to the environment and to
humans?
Climate change has and will continue to increase local, regional, and global
temperatures and alter weather patterns. As Esty points out, these changes
will lead to more severe weather events and natural disasters, ultimately
disrupting communities and infrastructure around the world.
“We also know that there will be devastating impacts to species and ecosystems
that humans don’t directly connect to or rely on,” Esty adds. “The stress of
increased temperatures and ocean acidification may prove too much for certain
species, causing them to collapse.”
Increasing temperatures will also melt glaciers at the Earth’s poles, which
will not only affect the species that live there, but will also cause global
sea level rise. This will impact coastal communities and ecosystems by eroding
or engulfing the land and heightening the risk of severe flooding.
“Because of the historically stable climate, we’ve developed a robust
civilizational infrastructure that is geographically anchored,” Massie
explains. “You can’t just take farmland that’s been developed over the course
of hundreds of years and move it north every three to five years.
As Climate Scientist Katharine Hayhoe says, if it were five
thousand years ago, as the sea levels rise, we would just pick up our coastal
encampments and move them further inland. But that’s hard to do, if your
coastal encampment is modern New York City or Hong Kong.”
A change in weather patterns will also have serious consequences for our
global food system.
“Changes in rainfall patterns and new periods of drought are particularly
concerning, as they may alter the lands that are suitable for food production
as well as the types and amounts of crops that can successfully grow and feed
our global population,” Esty says.
Massie points out that these disruptions to our homes, infrastructure and food
systems will challenge the equitable access to the necessities of life and put
great stress on the social fabric of humanity.
“The climate crisis has a number of cascading and interacting effects that are
already disrupting the foundations of our civilization and causing massive
public health problems–including 8.7 million deaths annually from the fossil
fuel particulate matter alone.
"Very importantly, climate impacts
intensify existing inequalities rather than reducing them–while also creating
new ones,” Massie says.
Massie goes on to explain that many communities around the world who will
experience the most devastating effects of climate change have often
contributed the least to the crisis and/or are least equipped to protect
themselves.
“Island Nations, for example, have contributed virtually nothing to climate
change, and yet they may have the physical home for their sense of belonging,
their national identity and culture completely wiped out by sea level rise,”
Massie explains.
“In Miami, the Haitian community is under
pressure to leave Little Haiti, which sits on elevated ground, as real estate
developers look to make way for wealthier, mostly white new residents fleeing
the beachfront flood zone as sea levels rise.
"There are examples
everywhere. The fossil fuel economy requires sacrifice zones, and sacrifice
zones require racism and other hierarchies … It’s important to include in the
definition of the climate crisis that it is a crisis of social inequality.”
What is being done to prevent and prepare for climate change?
Our experts explain that there are two key approaches to prevent and prepare
for climate change: mitigation and adaptation.
“Mitigation is the attempt to reduce the amount of greenhouse gas emissions
going into the atmosphere,” Esty explains. “It also includes efforts to
increase and protect the sinks that are absorbing carbon dioxide.”
There are a wide range of mitigation efforts happening at the local, regional,
country, and international scales. A key area of focus is moving towards
energy efficiency and a transition to a clean energy grid, which is one that
relies on renewable energy sources like solar, wind, and hydro power that do
not emit greenhouse gases.
This shift has implications for
transportation and shipping, industry and manufacturing, agriculture,
construction, and our material consumption as we know it.
"For
decades, countries around the world have collaboratively committed to reducing
global emissions through international treaties like the Paris Climate
Agreement, and individual regions, states, and cities have put forth policies
and plans to reduce emissions domestically.
Esty mentions a new component of climate change mitigation currently being
researched by scientists that is meant to deal with the GHGs we have already
emitted.
This area of research is called “geoengineering”, which
is the deliberate large-scale manipulation of an environmental process that
affects the Earth’s climate, in an attempt to counteract the effects of global
warming.
Esty explains that this strategy involves everything from
designing technologies to reflect solar radiation back into space to
developing man-made ways to capture or ‘sequester’ carbon and store it in the
ground.
Importantly, while geoengineering may help to reduce some of the severe
impacts of climate change as we transition our energy grid, the human
alteration of natural global processes comes with its own set of ethical
concerns.
The second key approach to preparing for climate change is called
adaptation.
“Adaptation is simply figuring out how we as a society can live with at least
some of the impacts of climate change,” Esty says. “Sometimes this is
described as resilience, or hardening ourselves to the changes in weather,
temperature, and systems that will undoubtedly come.”
This might involve moving or retrofitting coastal homes, roads, rail lines,
and power plants that are under increased risks of flood due to sea level
rise, or adding additional green spaces to cool down urban areas that will
experience extreme heat as temperatures rise.
Massie explains that the inequities of climate change are also apparent within
access to mitigation and adaptation resources. For example, while adaptation
efforts are expected to save money down the line, they take a large amount of
upfront investment, which is something that not all communities have.
Truly mitigating and equitably adapting to climate change, Massie believes,
will require a shifting of individual mindsets and social policies.
“You cannot imagine getting to a resilient, zero-carbon economy and society
without major interventions toward equality and toward a different set of
relationships among humans and with nature,” Massie says.
“Our
entire mode of being has developed as a complex, interconnected system, and
our energy source can’t be simply severed from that.”
What role do individuals play in mitigating and/or adapting to climate
change?
“To meaningfully take on climate change, we need to be hugely ambitious,”
Massie says. “It is not just the responsibility of government, but also all of
society and all of culture. Scientists have agreed that the worst impacts can
almost certainly be avoided, but to do that we need the broadest possible
public engagement.”
When it comes to mitigating climate change, Esty adds that in the near future,
we should expect incentives to switch to more sustainable forms of
transportation, like electric vehicles or biking, as well as renewable energy.
The impact associated with one’s food choices will likely also become a public
concern.
“People should be prepared to pay for the harms they are in effect causing
when they consume high greenhouse gas emitting products, with meat consumption
being a particularly notable example,” Esty says.
In terms of adaptation, Esty says that it is imperative for individuals to
think about their risk to climate impacts like severe weather and to prepare
themselves, their property, and their community accordingly.
Massie points out that we will also need individuals to stand up for their
communities in an activist capacity to demand that their elected officials
move away from the interests of and reliance on fossil fuel companies and take
ambitious climate action.
“These are huge challenges that we as a society can meet, if we establish the
correct social, political and cultural context in which decisions get made,”
Massie says. “To get started properly, we have the technology we need–what we
don’t have yet is the will to implement it at the required scale and speed.
"We need intensely ambitious and community-minded action by
government at all levels and across the private sector, sustained for a long
time. In turn that requires a broad cultural shift toward civic engagement and
action–the mobilization of people coming together to push that forward–both
activists who are already deeply involved with the climate justice struggle
and, critically, the broader public as well.”
What is Yale Doing?
In 2020, Yale met its greenhouse gas emissions goal of reducing emissions by
43% below 2005 levels, despite a 21% growth in the campus footprint. This
achievement was made possible by countless individuals and academic and
operational departments on campus.
Some notable contributions to this goal include:
-
Significant investments in our energy supply. We updated our power plants
and increased our reliance on renewables like solar and geothermal energy.
-
Retrofits of older campus buildings to become more energy efficient.
-
Employment of
new design guidelines
to ensure for the highest standards of efficiency in new construction and
renovations while improving the usage of existing campus space.
-
Personal energy reductions through participation in initiatives like the
Yale Carbon Charge Recess Checklist.
In summer 2021, Yale announced a new emissions reductions target that includes
achieving zero actual carbon emissions — in other words, reducing carbon
emissions to zero without having to purchase carbon offsets — by 2050, and
reaching net zero emissions by 2035, or “zero” emissions after offsets and
other campus reductions in emissions are factored in.
More information can be found in the
full announcement
from Peter Salovey and Scott Strobel.
Links
