"There are no published scenarios depicting a pathway returning to 450 CO2‐e [emissions] by century's end without a negative emissions option when delayed participation is imposed. The vast majority of published 450 CO2‐e scenarios involve overshoot during the century and include a negative emissions technology."
Carbon capture, or multiplier?
"... so far much of carbon captured from bioenergy and other processes is ultimately used for Enhanced Oil Recovery – injected into depleted oil wells to create pressure enough to force remaining difficult to access oil out. This can hardly be considered 'sequestration' or an effective approach to solving the climate problem."
"Lands and ecosystems cannot at the same time both provide large quantities of biomass for bioenergy, and still securely act as 'carbon sinks.' It is not possible to have it both ways."
Broken climate needs fixing
"Those working on geoengineering are largely doing so reluctantly. The concern is that we need to ensure technology is available in case events occur more quickly than expected. The IPCC has not fully accounted for certain feedbacks involving black carbon, methane release, and the rapid loss of the Arctic summer sea ice. A technique like marine cloud brightening by spraying seawater onto clouds to increase their reflectivity, could save the sea ice and help cool the climate with relatively little side-effects that can be controlled with careful application."
"Ultimately a full, immediate transition to renewables is the right imperative, but it cannot happen overnight due to the engineering costs and practicalities. So we must reduce our carbon emissions while we are still relying on fossil fuels. Our current emissions trajectory is heading for catastrophe. CCS would allow us to draw down emissions during the transition to renewables.
Every component of CCS has been practiced separately in the industry for decades, so putting them altogether to minimise our carbon footprint makes sense. Several large-scale commercial CCS enterprises will become operational this year, such as the coal-fired plant in Kemper County.
100% renewable transition in 15 years: feasible?
"We can't hope to simply run over a carbon precipice and pulls ourselves back. Government targets must be much more ambitious. Our research has shown that we can run modern societies without relying on fossil fuels, and that transitioning to net zero carbon emissions by 2030 is technologically and economically feasible with the right approach."
"Biomass does have the potential to be very destructive, but if used sparingly it has a place as part of a wider strategy involving renewables, to create synthetic fuels useful for industry and transport. Bioenergy is important as a flexible backup to address long-term energy storage due to the intermittency and variability of renewable sources - but its use must be sustainable, based on 'second generation' non-food crops [e.g. forest and crop residues, municipal and construction waste], not encroach on land-use for food, and combined with extensive reforestation."
"The underlying assumption appears to be that business as usual [BAU] economic growth must be sustained, and industry and corporate profits must be protected and maintained. But if we focus on 'BAU economics', seeking and accepting only bargain basement options for addressing global warming - the costs will be far more severe."