So now planting trees may increase global warming?
Trees affect our climate, and therefore our weather, in three primary
ways: they lower temperatures, reduce energy usage and reduce or remove
air pollutants. Each part of the tree contributes to climate control,
from leaves to roots.
Leaves help turn down the thermostat. They cool the air through a process called evapotranspiration. Evapotranspiration is the combination of two simultaneous processes: evaporation and transpiration, both of which release moisture into the air. During evaporation, water is converted from liquid to vapor and evaporates from soil, lakes, rivers and even pavement. During transpiration, water that was drawn up through the soil by the roots evaporates from the leaves. It may seem like an invisible process to our eyes, but a large oak tree is capable of transpiring 40,000 gallons of water into the atmosphere during one year [source: USGS].
http://science.howstuffworks.com/nature/climate-weather/storms/trees-affect-weather1.htm
Under the RCP 4.5 scenario models show planting trees can decrease albedo, thus increase global temperature. Maybe that’s what’s causing global warming, all that silva culture that’s been going on for decades.
From phys.org, Should the role of afforestation in climate change mitigation policy be re-evaluated?
http://phys.org/news/2014-11-role-afforestation-climate-mitigation-policy.html
Leaves help turn down the thermostat. They cool the air through a process called evapotranspiration. Evapotranspiration is the combination of two simultaneous processes: evaporation and transpiration, both of which release moisture into the air. During evaporation, water is converted from liquid to vapor and evaporates from soil, lakes, rivers and even pavement. During transpiration, water that was drawn up through the soil by the roots evaporates from the leaves. It may seem like an invisible process to our eyes, but a large oak tree is capable of transpiring 40,000 gallons of water into the atmosphere during one year [source: USGS].
http://science.howstuffworks.com/nature/climate-weather/storms/trees-affect-weather1.htm
Under the RCP 4.5 scenario models show planting trees can decrease albedo, thus increase global temperature. Maybe that’s what’s causing global warming, all that silva culture that’s been going on for decades.
From phys.org, Should the role of afforestation in climate change mitigation policy be re-evaluated?
Afforestation (planting trees) to mitigate climate change could
cause warming rather than cooling globally due to non-carbon effects of
land use change, according to new research from the University of
Bristol.
Global land use change and its interaction with the climate
system is recognised as an important component of the Intergovernmental
Panel on Climate Change (IPCC)’s future climate scenarios.
New research led by T Davies-Barnard of Bristol’s Cabot Institute investigated the full effects of carbon and non-carbon impacts of land use change in the representative concentration pathways (RCPs), a range of socioeconomic scenarios for future climate.
The research team used an earth system model to investigate global temperature sensitivity to land use change in the RCP scenarios. Their study, published in Environmental Research Letters, is the first to assess the effect of land use in both afforestation and deforestation scenarios for the RCPs.
They found that in RCP 4.5, a mid-range future climate projection that includes afforestation to help mitigate climate change, the land use change resulted in a small net positive warming.
This was primarily due to the addition of new forest in mid-latitudes, which decreased the albedo (reflectivity of the earth’s surface) and increased local and global temperature.
This small net gain in global temperature could mean that RCP 4.5′s universal carbon tax, a proposed mitigation policy that incentivizes growing and preserving forest, may be counter-productive with respect to climate change.
Dr Davies-Barnard said: “Without looking at the full effects of land use change, afforestation policies to reduce climate warming could actually do the opposite.”
However, the researchers also recognise that afforestation and the avoidance of deforestation would undoubtedly have wider environmental benefits, such as preserving biodiversity and maintaining ecosystem services.
Dr Davies-Barnard said: “Our work shows a small warming from forest preservation and expansion, but is that really the most important thing when considering the loss of unique and irreplaceable tropical forests?
”
This study has shown that non-carbon impacts of land use change make a small but important contribution which has been overlooked in the RCPs and, thus, their effects need to be considered in future climate change scenarios.
Incorporating land use change in climate change mitigation policy also requires a consideration of broader environmental aims, with impacts not necessarily acting in synergy, the research suggests.
Abstract from the Environmental Research Letters Article
New research led by T Davies-Barnard of Bristol’s Cabot Institute investigated the full effects of carbon and non-carbon impacts of land use change in the representative concentration pathways (RCPs), a range of socioeconomic scenarios for future climate.
The research team used an earth system model to investigate global temperature sensitivity to land use change in the RCP scenarios. Their study, published in Environmental Research Letters, is the first to assess the effect of land use in both afforestation and deforestation scenarios for the RCPs.
They found that in RCP 4.5, a mid-range future climate projection that includes afforestation to help mitigate climate change, the land use change resulted in a small net positive warming.
This was primarily due to the addition of new forest in mid-latitudes, which decreased the albedo (reflectivity of the earth’s surface) and increased local and global temperature.
This small net gain in global temperature could mean that RCP 4.5′s universal carbon tax, a proposed mitigation policy that incentivizes growing and preserving forest, may be counter-productive with respect to climate change.
Dr Davies-Barnard said: “Without looking at the full effects of land use change, afforestation policies to reduce climate warming could actually do the opposite.”
However, the researchers also recognise that afforestation and the avoidance of deforestation would undoubtedly have wider environmental benefits, such as preserving biodiversity and maintaining ecosystem services.
Dr Davies-Barnard said: “Our work shows a small warming from forest preservation and expansion, but is that really the most important thing when considering the loss of unique and irreplaceable tropical forests?
”
This study has shown that non-carbon impacts of land use change make a small but important contribution which has been overlooked in the RCPs and, thus, their effects need to be considered in future climate change scenarios.
Incorporating land use change in climate change mitigation policy also requires a consideration of broader environmental aims, with impacts not necessarily acting in synergy, the research suggests.
Abstract from the Environmental Research Letters Article
Letter
Future land use change (LUC) is an important component of the
IPCC representative concentration pathways (RCPs), but in these
scenarios’ radiative forcing targets the climate impact of LUC only
includes greenhouse gases. However, climate effects due to physical
changes of the land surface can be as large. Here we show the critical
importance of including non-carbon impacts of LUC when considering the
RCPs. Using an ensemble of climate model simulations with and without
LUC, we show that the net climate effect is very different from the
carbon-only effect. Despite opposite signs of LUC, all the RCPs assessed
here have a small net warming from LUC because of varying
biogeophysical effects, and in RCP4.5 the warming is outside of the
expected variability. The afforestation in RCP4.5 decreases surface
albedo, making the net global temperature anomaly over land around five
times larger than RCPs 2.6 and 8.5, for around twice the amount of LUC.
Consequent changes to circulation in RCP4.5 in turn reduce Arctic sea
ice cover. The small net positive temperature effect from LUC could make
RCP4.5′s universal carbon tax, which incentivizes retaining and growing
forest, counter productive with respect to climate. However, there are
spatial differences in the balance of impacts, and potential climate
gains would need to be assessed against other environmental aims.
fforestation (planting
trees) to mitigate climate change could cause warming rather than
cooling globally due to non-carbon effects of land use change, according
to new research from the University of Bristol.
Read more at: http://phys.org/news/2014-11-role-afforestation-climate-mitigation-policy.html#jCp
Read more at: http://phys.org/news/2014-11-role-afforestation-climate-mitigation-policy.html#jCp
fforestation (planting
trees) to mitigate climate change could cause warming rather than
cooling globally due to non-carbon effects of land use change, according
to new research from the University of Bristol.
Read more at: http://phys.org/news/2014-11-role-afforestation-climate-mitigation-policy.html#jCp
Read more at: http://phys.org/news/2014-11-role-afforestation-climate-mitigation-policy.html#jCp
fforestation (planting
trees) to mitigate climate change could cause warming rather than
cooling globally due to non-carbon effects of land use change, according
to new research from the University of Bristol.
Read more at: http://phys.org/news/2014-11-role-afforestation-climate-mitigation-policy.html#jCp
Read more at: http://phys.org/news/2014-11-role-afforestation-climate-mitigation-policy.html#jCp
fforestation (planting
trees) to mitigate climate change could cause warming rather than
cooling globally due to non-carbon effects of land use change, according
to new research from the University of Bristol.
Read more at: http://phys.org/news/2014-11-role-afforestation-climate-mitigation-policy.html#jCp
Read more at: http://phys.org/news/2014-11-role-afforestation-climate-mitigation-policy.html#jCp
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