Most of this is quotations from The Synthesis Report Summary.
Optimism
Deep, rapid, and sustained reductions in greenhouse gas emissions would lead to a discernible slowdown in global warming within around two decades, and also to discernible changes in atmospheric composition within a few years (high confidence).
The rate of growth in emissions between 2010 and 2019 (1.3% year) was lower than that between 2000 and 2009 (2.1% year).
Maintaining emission-intensive systems may, in some regions and sectors, be more expensive than transitioning to low emission systems [however the question for business is, which is the most profitable on the whole, and which loses the least already made capital investment?]
The Situation with GHG Emissions
Global net anthropogenic GHG emissions have been estimated to be 59±6.6 GtCO2-eq in 2019
In 2019, atmospheric CO2 concentrations (410 parts per million) were higher than at any time in at least 2 million years (high confidence), and concentrations of methane (1866 parts per billion) and nitrous oxide (332 parts per billion) were higher than at any time in at least 800,000 years (very high confidence). [we are headed towards a non-human world.
Emissions reductions in CO2-FFI [from fossil-fuel combustion and industrial] due to improvements in energy intensity of GDP and carbon intensity of energy, have been less than emissions increases from rising global activity levels in industry, energy supply, transport, agriculture and buildings.
If the annual CO2 emissions between 2020–2030 stayed, on average, at the same level as 2019, the resulting cumulative emissions would almost exhaust the remaining carbon budget for 1.5°C (50%), and deplete more than a third of the remaining carbon budget for 2°C (67%). Estimates of future CO2 emissions from existing fossil fuel infrastructures without additional abatement already exceed the remaining carbon budget for limiting warming to 1.5°C (50%) (high confidence). [It is logical to assume that no new gas and oil sources are needed]
[Bad news is that at current rates of reduction ie policy failure we are locked-in for between 2 and 4 degrees increase. The higher ends of that is catastrophic.]
Some Effects
In all regions increases in extreme heat events have resulted in human mortality and morbidity (very high confidence). The occurrence of climate-related food-borne and water-borne diseases (very high confidence) and the incidence of vector-borne diseases (high confidence) have increased. In assessed regions, some mental health challenges are associated with increasing temperatures (high confidence), trauma from extreme events (very high confidence), and loss of livelihoods and culture (high confidence).
Economic damages from climate change have been detected in climate-exposed sectors, such as agriculture, forestry, fishery, energy, and tourism. Individual livelihoods have been affected through, for example, destruction of homes and infrastructure, and loss of property and income, human health and food security, with adverse effects on gender and social equity.(high confidence).
In urban areas, observed climate change has caused adverse impacts on human health, livelihoods and key infrastructure. Hot extremes have intensified in cities. Urban infrastructure, including transportation, water, sanitation and energy systems have been compromised by extreme and slow-onset events, with resulting economic losses, disruptions of services and negative impacts to well-being. Observed adverse impacts are concentrated amongst economically and socially marginalised urban residents.
[increasing drought, fires, infectious diseases, floods, displacement, glacier retreat, ocean acidification]
Challenges
There are widening disparities between the estimated costs of adaptation and the finance allocated to adaptation.
Climate finance growth has slowed since 2018
The IPCC still thinks Carbon Capture & Storage is required. which basically blows any optimism for me.
[However they recognise this problem]: Implementation of CCS currently faces technological, economic, institutional, ecological, environmental and socio-cultural barriers. Currently, global rates of CCS deployment are far below those in modelled pathways limiting global warming to 1.5°C to 2°C.
The report also says over-reliance tree planting and biomass crops paired with CCS, can have adverse socio-economic and environmental impacts, including on biodiversity, food and water security, local livelihoods and the rights of Indigenous Peoples, especially if implemented at large scales and where land tenure is insecure.
Net zero CO2 energy systems entail: a substantial reduction in overall fossil fuel use, minimal use of unabated fossil fuels, and use of carbon capture and storage in the remaining fossil fuel systems; electricity systems that emit no net CO2; widespread electrification; alternative energy carriers in applications less amenable to electrification; energy conservation and efficiency; and greater integration across the energy system (high confidence).
The press release also states: The pace and scale of what has been done so far, and current plans, are insufficient to tackle climate change.
Consequences of not acting now
The higher the magnitude and the longer the duration of overshoot, the more ecosystems and societies are exposed to greater and more widespread changes in climatic impact-drivers, increasing risks for many natural and human systems…. Overshooting 1.5°C will result in irreversible adverse impacts on certain ecosystems with low resilience, such as polar, mountain, and coastal ecosystems, impacted by ice-sheet, glacier melt, or by accelerating and higher committed sea level rise
The choices and actions implemented in this decade will have impacts now and for thousands of years (high confidence).
