Climate Crisis Advisory Group (CCAG) report: The Final Warning Bell

Climate Crisis Advisory Group (CCAG) report: The Final Warning Bell

I recently reviewed the Intergovernmental Panel on Climate Change (IPCC) – Sixth Assessment report ( which stated that climate change is widespread, rapid, and intensifying.

Unprecedented changes are being observed in every region and across the whole climate system as evidenced by the following:

  • CO₂ concentration is the highest in at least 2 million years. Methane and nitrous oxide, which are also greenhouse gases, are at higher concentrations than at any time in at least 800,000 years
  • Sea levels are rising at the fastest rate in at least 3000 years
  • The area of arctic sea ice is at its lowest level in at least 1000 years
  • Glaciers are retreating at the fastest rate in at least 2000 years

The report provides new estimates of the probability of exceeding the global warming level of 1.5°C in the next decades and finds that unless there are immediate, rapid, and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will not be achievable.

The report shows that emissions of greenhouse gases from human (anthropogenic) activities today are responsible for approximately 1.1°C of global warming since 1850, and finds that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming resulting in increasing heat waves, longer warm seasons and shorter cold seasons. On current unconditional pledges, the world is heading for around 3.2°C temperature rise leading to accelerated and irreversible impacts.

In response to this alarming report, the Climate Crisis Advisory Group published a report titled “The Final Warning Bell – The Most Important Assessment of Humanity’s Future on Earth to Date” (, which reinforces the existential threat to our planet.

The Climate Crisis Advisory Group (CCAG) is an independent group of experts encompassing a wide range of academic disciplines and comprises 15 experts from 11 nations. CCAG members include leading authorities in climate science, carbon emissions, energy, environment, and natural resources, and number among their members the UK Government’s Chief Scientific Advisor from 2000 to 2007.

The report states unequivocally that a rise of 1.5°C of warming is now inevitable and that every fraction of a degree of additional warming will exacerbate the climate risks humanity is facing. The Arctic Circle is probably already beyond its tipping point, as discussed in CCAG’s July 2021 report. In August, rainfall occurred on the highest peak in Greenland for the first time in recorded history.

As the IPCC report makes clear, the coming 9 years until 2030 are critically important, and will switch on changes that will impact humanity for the coming centuries, if not millennia.

Even if we are successful in reaching net-zero CO₂ emissions by mid-century, atmospheric CO₂ equivalent (CO₂e) will continue to rise, potentially to as high as 540 parts per million (ppm). We started to take global action on emissions (and CO2 levels) from the late 1990s with the Kyoto Protocol. Back then the aim was to keep the amount of CO₂ in the atmosphere below 350 parts per million. In May 2021 CO₂ levels in the Mauna Loa observatory in Hawaii, which is the longest record we have of CO₂ in the atmosphere, hit 419 ppm.

In essence, there is a contradiction between the implications of the IPCC report and the 2015 Paris Agreement – allowing warming of 1.5°C will be disastrous, and anything beyond that, catastrophic. While carbon emissions reduction is essential, it will not be enough to prevent continuing sea-level rise, thawing permafrost with the release of methane, and other climate-related changes. The stark finding of the CCAG report is that net-zero by 2050 is now too little too late and net-negative strategies are the only viable option. We should view the IPCC report as the final warning – there is no room left for maneuver and no carbon budget left to spend.

Reducing greenhouse gas emissions is critical to humanity’s survival and must be undertaken deeply and rapidly at a pace and scale more ambitious than hitherto achieved. To date, our actions have not yet begun to reduce the amount of CO₂ added to the atmosphere each year. Every year that we delay beginning sustained global emission reductions places a burden on the future pace of emissions reductions required to meet the Paris Agreement.

We must expeditiously start removing greenhouse gases from the atmosphere in order to repair our critically damaged climate systems. Any country that has committed to net zero emissions has implicitly committed to greenhouse gas removal. Greenhouse gas removal is implicit, to a greater or lesser degree, in all five possible scenarios (Shared Socio-economic Pathways, SSPs) posited by the IPCC to illustrate the climate response to various levels of greenhouse gas emissions. Almost all pathways are predicated on an assumption that unproven technologies will remove more CO₂ from the atmosphere than is emitted.

In the preparations for COP26, the 2021 United Nations Climate Change Conference in Glasgow in November, it is critically important to acknowledge the verity that without greenhouse gas removal we cannot hit net-zero or continue to progress towards the negative emissions required in the second half of this century.

Climate repair requires removing greenhouse gases from the atmosphere in prodigious quantities and ameliorating the melting of the polar ice caps in order to correct the volatile weather patterns, slow down ice-melt, stabilise sea level, and break the feedback loops that relentlessly accelerate global warming.

Climate Repair offers a scalable, safe recipe for future climate stability. It comprises:

  • Deep and rapid emissions reduction through energy demand reductions, decarbonisation of electricity and other fuels, electrification of energy end-use, and reductions in agricultural emissions protecting food security.
  • Greenhouse gas removal (through the capture and sequestration of carbon and methane), removing greenhouse gases to restore atmospheric concentrations to 350ppm CO₂ equivalent – a fall of approximately 100ppm – by 2100.
  • Repair of parts of the climate system that have passed tipping points – such as refreezing the North and South poles (including the Himalayas).
  • Promotion of agile political and financial responses.

Technical greenhouse gas removal solutions include inter alia:

  1. Capturing carbon at point of emission: e.g., the incorporation of ‘carbon capture’ into manufacturing processes such as steel and concrete – so that CO₂ emitted is captured and stored or used in the manufacturing process, or in ‘mineralisation’.
  2. Removing from the atmosphere excess greenhouse gases already emitted. Direct Air Capture technologies are under development – where CO₂ and other greenhouse gases are pulled directly from the air for sequestration.
  3. More complex technologies are required for the removal or oxidation of methane from methane-emitters and from the atmosphere (methane is a much more serious greenhouse gas per molecule than CO₂).

Nature-based solutions include:

  1. Land-based solutions which remove CO₂ from the atmosphere through conserving and restoring natural ecosystems and through agricultural systems management.
  2. Ocean-based solutions such as marine up-welling, which extends the scale of marine kelp, sea grasses, and seaweed farms, offering new carbon sinks, plus production of food for cattle – which increases milk yields whilst lowering methane emissions from livestock.

Stabilising the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions combined with deep and concentrated greenhouse gas removal through the capture and sequestration of carbon and methane.