A new analysis suggests that despite recent emissions reductions gains, a colossal deployment of technological solutions is required if nations are to keep within the two-degree guardrail set by the Paris Agreement.
To stay under 2°C, the global economy must be carbon neutral—producing no more CO2 than can be absorbed by oceans, forests and technology—by mid-century.
The main difficulty in being able to rigorously assess how we are doing in mitigating climate change is that most countries use different metrics. However new research published in Nature Climate Change, introduces a methodology for tracking process.
Researchers developed a series of simple nested indicators that relate carbon emissions to their drivers: GDP growth, energy intensity, fossil fuel’s share of the energy mix, and carbon intensity of fossil fuel use.
They then applied these indicators to the current situation, and their results offer both good news and bad news.
They confirmed that 2014, 2015 and now likely 2016 will have seen no growth in emissions. The plateau has primarily been driven by China’s decrease in growth in coal, cement and steel use; in the United States by its widespread shift from coal to shale gas; and in the European Union by a larger share of renewable energy generation.
Lower GDP growth in the EU, US and China (2005-2015 was down sharply on the 1995-2005 period) has also played a major role, as have improvements in energy efficiency and a shift to light industry and services (which are less energy intensive) as countries, particularly China, develop.
The rapid expansion of solar and wind energy, while also a positive trend, is not displacing growth in fossil fuels. Renewables’ share of global energy consumption remains less than three percent of the total, while fossil fuels represent 87 percent. Furthermore, in the absence of large-scale storage, accommodating more intermittent renewable energy will require more back-up capacity, typically from the sources of our climate woes—coal, oil and gas.
With most modeling assessments reliant on negative emissions technologies to stay below 2 °C , this new report examines the most common scenario of coupling bionergy with carbon capture and storage (BECCS). “It is uncertain whether bioenergy can be sustainably produced and made carbon-neutral at the scales required,” the researchers noted, alongside the reality that only a handful of CCS plants are operating, compared to the thousands needed by 2030.
In the absence of such deployment of BECCS, we need to have a much more disruptive decline in the use of fossil fuels. However the researchers note a lack of studies exploring whether scenarios involving ‘transformational lifestyle and behavioural changes coupled with low CCS and high rates of renewables’ would also achieve the mitigation demanded. Other non-CCS options include solar radiation management, but again, there is a dearth of studies on this.
Hydroelectricity has long been assumed to be a cornerstone of any future low-carbon economy, but disappearing glaciers are altering the equation