This comes as a spanner in the works of those working night and day to evolve policies and mechanisms to arrest climate change. The implementation of climate engineering technologies as a last ditch effort to combat the escalating effects of climate change could, in fact, make things worse, assert a team of researchers.
This comes as a spanner in the works of those working night and day to evolve policies and mechanisms to arrest climate change. The implementation of climate engineering technologies as a last ditch effort to combat the escalating effects of climate change could, in fact, make things worse, assert a team of researchers.
According to a modelling study published in Nature Communications on Tuesday, climate engineering is likely to be either relatively ineffective or might even result in severe climatic side effects.
With the rate of climate change itself far outpacing mitigation strategies, climate engineering as a potential means of preventing catastrophic climate change has been attracting considerable interest from both climatologists as well as governments. Climate engineering, also known as geoengineering, refers to manmade technologies specifically designed to manipulate global climate. While the potential effectiveness of individual methods has been tested, there have been few attempts to compare them.
David Keller of the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany, and colleagues used an Earth system model to evaluate the effectiveness and potential negative side-effects of five climate engineering technologies when deployed continuously, and at scales as large as currently deemed possible, under a high CO2-emission scenario.
There was a reason why the team undertook this study. They wrote, "A previous comparison of the radiative forcing potential of different climate engineering methods addressed the question of how efficient the methods are at preventing global warming. However, the analytical methodology that was used did not allow for the quantification of side effects and the possible feedbacks in the climate system that may cause a method to be more or less effective than predicted." In other words, there was a need to quantify the side-effects.
The team has shown that, even when several technologies are combined, climate engineering would be unable to prevent mean surface temperatures from rising well above 2° C by the year 2100. In addition, they have projected that all technologies are, individually, either relatively ineffective with limited warming reductions (less than 8 per cent), or that they have potentially severe side-effects and cannot be stopped without returning large amounts of stored CO2 to the atmosphere and causing rapid climate change.
The teams’ findings strongly suggest that climate engineering technologies should not be depended upon to prevent future warming and that CO2 mitigation is likely the most effective way to prevent further climate change.
The researchers concluded with a word of caution, "Climate engineering does not appear to be an alternative option, although it could possibly be used to compliment mitigation. However, if climate engineering is seriously considered as one of the means of preventing climate change, care must be taken when evaluating whether the potential reductions in atmospheric carbon and temperature of a particular method are worth the risks and costs of its side effects."
|
Side effects of the climate engineering methods
|
|
Method
|
Desired effects
|
Side effects
|
|
Afforestation
|
Alters terrestrial productivity and carbon storag Increases regional precipitation Increases local evaporative cooling
|
Decreases the local surface albedo Increases adjacent regional surface air temperatures Increases regional freshwater ocean input thereby reducing coastal salinity and altering currents and stratification
|
|
Ocean upwelling
|
Increases marine productivity, except in some equatorial upwelling regions Alters terrestrial productivity Alters ocean circulation, salinity, and stratification Reduces soil temperatures
|
Cools surface atmosphere Increases surface-ocean pCO2 and acidification in equatorial upwelling regions ·Reduces precipitation ·Enhances terrestrial carbon storage Reduces sea-ice melting Increases ocean deoxygenation and the volume of oxygen minimum zones Imbalances the global heat budget Rapid climate change occurs when Stopped
|
|
Ocean alkalinization
|
Reduces the rate of ocean acidification in the alkalized region
|
Reduces the rate at which the saturation states of aragonite and calcite decrease
|
|
Ocean iron
|
Increases marine productivity south of 40 ° S Reduces marine productivity north of 40 ° S
|
Increases surface-ocean pCO2 and acidification in some of the fertilized region Increases ocean deoxygenation, but decreases the volume of tropical oxygen minimum zones
|
|
Solar radiation management
|
Alters terrestrial productivity and respiration Decreases surface-ocean pCO2 and the rate of ocean acidification
|
Alters precipitation patterns Reduces total precipitation Alters the carbon cycle Reduces ocean deoxygenation Atmospheric CO2 continues to accumulate and rapid climate change
|
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
)
){kind=small}
){kind=small}
)
)
)
)
)
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}