298
of the same citation, all quotes not otherwise attributed, are attributable to (IPCC
2013, 2014a, b).
Even without consideration of human-induced changes to the climate, many elements of FEW systems in many locations are unsustainable for non-climatic reasons, such as the degradation of local ecosystem functions. Thus, mitigating or
adapting to climate change is only part of developing sustainable FEW systems that
meet the needs of human societies.
11.2 Background
There are many well-known natural cycles in the earth’s climate system. There is
also significant natural variability in weather from year-to-year, including the occurrence of extreme events such as droughts, storms, heatwaves, and extremely cold
conditions.
Without considering anthropogenic climate change, it would be possible to
model FEW systems based on long-term observations of climate conditions and the
factors that influence them, including seasonal cycles, variations, and the frequency
of extreme events. However, anthropogenic climate change requires recognition of
changes (some nonlinear) so that the future will not look like the past. Modeling
future climates means combining an appreciation for both natural climate patterns
and their variations and the impacts of human-induced changes to the earth’s climate system.
Anthropogenic emissions of greenhouse gases (GHGs) exist alongside natural
sources and sinks of greenhouse gases intensifying the earth’s natural greenhouse
effect. Emissions of carbon dioxide and methane are the most significant anthropogenic sources of GHGs, about 72%, and 19% respectively in 2016 (JanssensMaenhout et al. 2017). Both the level of GHGs present in the earth’s atmosphere
and the rate of increase are unprecedented over the period of human history.
Anthropogenic emissions of GHGs are changing the earth’s climate in many
ways, including the general warming of the atmosphere. The earth’s lower atmosphere is about 0.8 °C (1.4 °F) warmer since 1880. While average global temperature is a useful and widely cited metric of climate change, it is only one aspect of the
climate and in most practical situations, not the most useful (see Chap. 13).
Anthropogenic climate change results in a wide variety of effects and impacts
which manifest themselves in different ways in different locations.
The United Nations Framework Convention on Climate Change (UNFCCC) has
a stated goal to “stabilize greenhouse gas concentrations in the atmosphere at a level
that would prevent dangerous anthropogenic interference with the climate system.”
In the 2015 Paris Agreement, the nations of the world adopted a goal of “keeping a
global temperature rise this century well below 2 °C above pre-industrial levels and
to pursue efforts to limit the temperature increase even further to 1.5 °C.”
Some effects of climate change, such as sea level rise and the average number of
days of temperature extremes, have long-term incremental impacts on all aspects of
FEW systems, from production to utilization to population movements. The ability
P. Saundry
of the same citation, all quotes not otherwise attributed, are attributable to (IPCC
2013, 2014a, b).
Even without consideration of human-induced changes to the climate, many elements of FEW systems in many locations are unsustainable for non-climatic reasons, such as the degradation of local ecosystem functions. Thus, mitigating or
adapting to climate change is only part of developing sustainable FEW systems that
meet the needs of human societies.
11.2 Background
There are many well-known natural cycles in the earth’s climate system. There is
also significant natural variability in weather from year-to-year, including the occurrence of extreme events such as droughts, storms, heatwaves, and extremely cold
conditions.
Without considering anthropogenic climate change, it would be possible to
model FEW systems based on long-term observations of climate conditions and the
factors that influence them, including seasonal cycles, variations, and the frequency
of extreme events. However, anthropogenic climate change requires recognition of
changes (some nonlinear) so that the future will not look like the past. Modeling
future climates means combining an appreciation for both natural climate patterns
and their variations and the impacts of human-induced changes to the earth’s climate system.
Anthropogenic emissions of greenhouse gases (GHGs) exist alongside natural
sources and sinks of greenhouse gases intensifying the earth’s natural greenhouse
effect. Emissions of carbon dioxide and methane are the most significant anthropogenic sources of GHGs, about 72%, and 19% respectively in 2016 (JanssensMaenhout et al. 2017). Both the level of GHGs present in the earth’s atmosphere
and the rate of increase are unprecedented over the period of human history.
Anthropogenic emissions of GHGs are changing the earth’s climate in many
ways, including the general warming of the atmosphere. The earth’s lower atmosphere is about 0.8 °C (1.4 °F) warmer since 1880. While average global temperature is a useful and widely cited metric of climate change, it is only one aspect of the
climate and in most practical situations, not the most useful (see Chap. 13).
Anthropogenic climate change results in a wide variety of effects and impacts
which manifest themselves in different ways in different locations.
The United Nations Framework Convention on Climate Change (UNFCCC) has
a stated goal to “stabilize greenhouse gas concentrations in the atmosphere at a level
that would prevent dangerous anthropogenic interference with the climate system.”
In the 2015 Paris Agreement, the nations of the world adopted a goal of “keeping a
global temperature rise this century well below 2 °C above pre-industrial levels and
to pursue efforts to limit the temperature increase even further to 1.5 °C.”
Some effects of climate change, such as sea level rise and the average number of
days of temperature extremes, have long-term incremental impacts on all aspects of
FEW systems, from production to utilization to population movements. The ability
P. Saundry