Is Net-Zero Emissions Actually Possible?
The UK, like several other countries, aims to deliver “net-zero” greenhouse gas (GHG) emissions by the year 2050. This is in line with the Intergovernmental Panel on Climate Change (IPCC). IT has been highlighted that to achieve this target, “negative emissions” will be required. New reports say that the targets are indeed achievable however, let’s analyze the findings and see if we agree.
The International Energy Agency (EIA) Report
In a 227-page report, the International Energy Agency said it is possible to achieve net-zero emissions by 2050 and limit warming to 1.5 C. But it will require a wholesale makeover of the world’s energy system starting today.
Dramatic action is required in the next decade to have any hope achieving a net-zero goal by 2050, IEA said. Where electric vehicles now account for 5% of global automobile sales, they will need to represent 60% of new automobile purchases in 2030. Annual renewable installations, which hit a record 280 gigawatts last year, will need to exceed 1,000 GW. And energy efficiency improvements will need to grow by 4% annually, roughly three times their current rate.
“The scale and speed of the efforts demanded by this critical and formidable goal—our best chance of tackling climate change and limiting global warming to 1.5° C—make this perhaps the greatest challenge humankind has ever faced,” IEA Executive Director Fatih Birol said in a statement.
IEA’s findings are significant on several levels. Net-zero road maps are traditionally the provenance of academics, International Panel on Climate Change modelers and green-hued think tanks. The IEA, an agency established in response to the oil crisis of 1973 and 1974, has long been pilloried by greens for failing to accurately capture the growth of renewables and for a hesitant embrace of the energy transition.
A net-zero target contains within it two related, but different responses to the problem of rising temperatures. The first is to stop releasing GHGs in the first place, by cutting emissions. The second is to remove CO2 from the atmosphere using “negative emissions technologies” (NETs).
A net-zero target is met when these two balance – when residual emissions are offset by CO2 removals. The problems lie in the interaction between these two. If we pay more attention to removals, how might that affect releases?
Even if negative emissions simply substitute for feasible emissions reductions, there could be negative side-effects. Unlike carbon emissions prevented by mitigation, carbon put into forests, soils or even geological stores could leak back into the atmosphere.
Net-zero plans that rely on promises of future carbon removal – instead of reducing emissions now – are, therefore, placing a risky bet. If the technologies anticipated to remove huge quantities of carbon in the 2040s and 2050s fail to work as expected – or lead to rebounds in emissions from land-use change, for example – then it might not be practical to compensate for the cumulative emissions from mitigation foregone between now and then.
For such targets to be achieved by 2050, almost 90% of the electricity produced globally will need to come from renewable sources – with 70% from solar and wind. Current outputs are far from achieving these targets and more in the way of improved infrastructure is required to reach the end goal.
Achieving Negative Emissions
Many scientists and experts agree one of the most promising technologies to achieve negative emissions is bioenergy with carbon capture and storage (BECCS). This approach uses biomass – sourced from sustainably managed forests – to generate electricity. As the forests used to create biomass absorbs CO2 while growing, the CO2 released when it is used as fuel is already accounted for, making the whole process low carbon.
By then capturing and storing any CO2 emitted (often in safe underground deposits), the process of electricity generation becomes carbon negative, as more carbon has been removed from the atmosphere than has been added.
Globally, the destruction of a third of coastal and marine wetlands to make way for houses, ports and other commercial activity is shrinking the size of the ‘blue carbon sink. Exposed soils also release CO2, turning coastal ecosystems from net absorbers of greenhouse gases to net sources. Carbon emissions from degraded mangroves, tidal marshes, and seagrasses are thought to be equivalent to 3–19% of those produced annually from deforestation, though some large uncertainties still remain.
Conserving and restoring coastal ecosystems so that they can continue to draw CO2 out of the air has been suggested as a way to mitigate climate change. Global projects to coordinate research and raise awareness about so-called ‘blue carbon’ habitat restoration highlight the many benefits on top of reducing emissions, such as providing nursery grounds for wildlife and offering protection against coastal storms.