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15 key findings from the IPCC mitigation report

Energydesk staff
License: All rights reserved. Credit: Bernd Roemmelt/Greenpeace

Here are the main findings from the IPCC's WGIII report, taken the Summary for Policymakers (SPM), the Technical Summary and underlying chapters, seen by Energydesk:

1) Serious emissions cuts haven’t really started yet - greenhouse gases emitted still rising
"Total anthropogenic GHG [greenhouse gas] emissions have continued to increase over 1970 to 2010 with larger absolute decadal increases toward the end of this period (high confidence). Despite a growing number of climate change mitigation policies, annual GHG emissions grew on average by 1.0 gigatonne carbon dioxide equivalent (GtCO2eq) (2.2%) per year from 2000 to 2010 compared to 0.4 GtCO2eq (1.3%) per year from 1970 to 2000 (Figure SPM.1). Total anthropogenic GHG emissions were the highest in human history from 2000 to 2010 and reached 49 (±4.5) GtCO2eq/yr in 2010. The global economic crisis 2007/2008 only temporarily reduced emissions. [1.3, 5.2, 13.3, 15.2.2, Box TS.5, Figure 15.1] [SPM Page 5]

2) If we carry on as we are it will result in 3.7 to 4.8 degrees of warming by the end of the century

“Without additional efforts to reduce GHG emissions beyond those in place today, emissions growth is expected to persist driven by growth in global population and economic activities. Baseline scenarios, those without additional mitigation, result in global mean surface temperature increases in 2100 from 3.7 to 4.8°C compared to pre‐industrial levels (median values; the range is 13 2.5°C to 7.8°C when including climate uncertainty, see Table SPM.1).” [SPM page 8]

3) It is not too late to limit warming to less than 2°C – or maybe even 1.5°C 
“Scenarios reaching atmospheric concentrations levels of about 450 ppm CO2eq by 2100 (consistent with a likely chance to keep temperature change below 2°C relative to preindustrial levels) include substantial cuts in anthropogenic GHG emissions by mid-century through large-scale changes in energy systems and potentially land use (high confidence). Scenarios reaching these concentrations by 2100 are characterized by lower global GHG emissions in 2050 than in 2010, 40% to 70% lower globally, and emissions levels near zero GtCO2eq or below in 2100.” [SPM page 11]

”Only a limited number of studies have explored scenarios that are more likely than not to bring temperature change back to below 1.5°C by 2100 relative to preindustrial levels; these scenarios bring atmospheric concentrations to below 430 ppm CO2eq by 2100 (high confidence). (…) In these scenarios, the cumulative CO2 emissions range between 655-815 GtCO2 for the period 2011-2050 and between 90-350 GtCO2 for the period 2011-2100. Global CO2-eq emissions in 2050 are between 70-95% below 2010 emissions, and they are between 110-120% below 2010 emissions in 2100.” SPM. P. 22 and footnote.” [SPM Page 19] 

4) Fossil fuels contributed 78% to the total GHG emissions increase between 1970 and 2010
“CO2 emissions from fossil fuel combustion and industrial processes contributed about 78% of the total GHG emission increase from 1970 to 2010, with a similar percentage contribution for the period 2000-2010 (high confidence). Fossil fuel-related CO2 emissions reached 32 (±2.7) GtCO2/yr, in 2010, and grew further by about 3% between 2010 and 2011 and by about 1-2% between 2011 and 2012.”  [SPM page 5]

5) 2000-2010 was the decade of coal 

“In the last decade, the main contributors to emission growth were a growing energy demand and an increase of the share of coal in the global fuel mix.” [SPM Page 29]

“Increased use of coal especially in developing Asia is exacerbating the burden of energy-related GHG emissions (Figure TS.6).” [Technical Summary page 18]

“The energy supply sector is the largest contributor to global greenhouse gas emissions (robust evidence, high agreement). GHG emissions from the energy sector grew more rapidly between 2001 and 2010 than in the previous decade; their growth accelerated from 1.7% per year from 1991-2000 to 3.1% per year from 2001-2010. The main contributors to this trend are an increasing demand for energy services and a growing share of coal in the global fuel mix.” [Technical Summary. Page 43]

6) We need to head towards fossil fuel phase out and zero net emissions

“Mitigation scenarios reaching around 450 ppm CO2eq concentrations by 2100 show large‐scale global changes in the energy supply sector (robust evidence, high agreement). In these selected scenarios, global CO2 emissions from the energy supply sector are projected to decline over the next decades and are characterized by reductions of 90% or more below 2010 levels between 2040 and 2070. Emissions in many of these scenarios are projected to decline to below zero thereafter.” [SPM. Page 21]

“The stabilization of greenhouse gas concentrations at low levels requires a fundamental transformation of the energy supply system, including the long-term phase-out of unabated fossil fuel conversion technologies and their substitution by low-GHG alternatives (robust evidence, high agreement). Concentrations of CO2 in the atmosphere can only be stabilized if global (net) CO2 emissions peak and decline toward zero in the long term. Improving the energy efficiencies of fossil power plants and/or the shift from coal to gas will not by itself be sufficient to achieve this.” [Technical Summary Page 43]

7) Fossil fuel companies face reduced revenues 
“Mitigation policy could devalue fossil fuel assets, and reduce revenues for fossil fuel exporters, but differences between regions and fuels exist (high confidence). Most mitigation scenarios are associated with reduced revenues from coal and oil trade for major exporters (high confidence). The effect of mitigation on natural gas exporters revenues is more uncertain with some studies showing possible benefits for export revenues in the medium term until about 2050 (medium confidence). The availability of CCS would reduce the adverse effect of mitigation on the value of fossil fuel assets (medium confidence). [6.3.6, 6.6, 14.4.2]” (SPM. Page 19)

8) To stop the worst of climate change from happening, low carbon technologies share needs to grow to 80% by 2050

“In general, the rapid decarbonization of electricity generation is realized by a rapid reduction of conventional coal power generation associated with a limited expansion of natural gas without CCS over the near term [6.8, 7.11]. In the majority of stringent mitigation scenarios (430-530 ppm CO2-eq), the share of low-carbon energy in electricity supply increases from the current share of around 30% to more than 80% by 2050. In the long run (2100), fossil power generation without CCS is phased out almost entirely in these scenarios (Figure TS.18).” [Technical summary Page 43]

9) Renewable energy is ready to boom and comes with benefits including less air pollution, more security and fewer severe accidents than conventional energy generation
“Since AR4, renewable energies (RE) has become a fast growing category in energy supply, with many RE technologies having advanced substantially in terms of performance and cost, and a growing number of RE technologies has achieved technical and economic maturity (robust evidence, high agreement). Some technologies are already economically competitive in various settings. Levelized costs of photovoltaic systems fell most substantially between 2009 and 2012, and a less extreme trend has been observed for many others RE technologies. RE accounted for just over half of the new electricity-generating capacity added globally in 2012, led by growth in wind, hydro and solar power.” [TS Page 43]

“Since AR4, many RE technologies have demonstrated substantial performance improvements and cost reductions, and a growing number of RE technologies have achieved a level of maturity to enable deployment at significant scale (robust evidence, high agreement). Regarding electricity generation alone, RE accounted for just over half of the new electricity‐generating capacity added globally in 2012, led by growth in wind, hydro and solar power. However, many RE technologies still need direct and/or indirect support, if their market shares are to be significantly increased; RE technology policies have been successful in driving recent growth of RE. Challenges for integrating RE into energy systems and the associated costs vary by RE technology, regional circumstances, and the characteristics of the existing background energy system (medium evidence, medium agreement).” [SPM. Page 23] 

“The use of RE is often associated with co-benefits, including the reduction of air and water pollution, local employment opportunities, few severe accidents compared to some other energy supply technologies, as well as improved energy access and security (medium evidence, medium agreement) (Table TS.3). At the same time, however, some RE technologies can have technology and location-specific adverse side-effects, which can be reduced to a degree through appropriate technology selection, operational adjustments, and siting of facilities. [7.9]” [Technical Summary. Page 44]

10) Using energy more smartly plays a fundamental role in emission cuts

“Efficiency enhancements and behavioural changes, in order to reduce energy demand compared to baseline scenarios without compromising development, are a key mitigation strategy in scenarios reaching atmospheric CO2eq concentrations of about 450 or 500 ppm by 2100 (robust evidence, high agreement). Near‐term reductions in energy demand are an important element of cost‐effective mitigation strategies, provide more flexibility for reducing carbon intensity in the energy supply sector, hedge against related supply‐side risks, avoid lock‐in to carbon‐intensive infrastructures, and are associated with important co‐benefits. Both integrated and sectoral studies provide similar estimates for energy demand reductions in the transport, buildings and industry sectors for 2030 and 2050 (Figure SPM.8).” [SPM. Page 21]

11) Nuclear is on the decline and excluding it does not much increase the costs of mitigation
“Nuclear energy is a mature low-GHG emission source of baseload power but its share of global electricity generation has been declining (since 1993). Nuclear energy could make an increasing contribution to low-carbon energy supply, but a variety of barriers and risks exist (robust evidence, high agreement). Those include: operational risks, and the associated concerns, uranium mining risks, financial and regulatory risks, unresolved waste management issues, nuclear weapon proliferation concerns, and adverse public opinion (robust evidence, high agreement). New fuel cycles and reactor technologies addressing some of these issues are being investigated and progress in research and development has been made concerning safety and waste disposal.” [SPM, p23]

“Investigation of stringent mitigation scenarios (450ppm, 550ppm CO2-eq) have shown that the exclusion of nuclear power from the set of admissible technologies would only result in a slight increase of mitigation costs compared to the full technology portfolio (Figure TS.13).” [Technical Summary, p. 44]

12) CCS has not yet been applied to scale and many barriers remain
“Carbon dioxide capture and storage (CCS) technologies could reduce the life-cycle GHG emissions of fossil fuel power plants (medium evidence, medium agreement). While all components of integrated CCS systems exist and are in use today by the fossil fuel extraction and refining industry, CCS has not yet been applied at scale to a large, operational commercial fossil fuel power plant. CCS power plants could be seen in the market if this is incentivized by regulation and/or if they become competitive with their unabated counterparts if the additional investment and operational costs, caused in part by efficiency reductions, are compensated by sufficiently high carbon prices (or direct financial support). For the large-scale future deployment of CCS, well-defined regulations concerning short- and long-term responsibilities for storage are needed as well as economic incentives. Barriers to large-scale deployment of CCS technologies include concerns about the operational safety and long-term integrity of CO2 storage as well as transport risks. There is, however, a growing body of literature on how to ensure the integrity of CO2 wells, on the potential consequences of pressure build-up within a geologic formation caused by CO2 storage (such as induced seismicity), and on the potential human health and environmental impacts from CO2 that migrates out of the primary injection zone.” [SPM, page 24]

13) Costs of action are tiny when put into context
“Estimates of the aggregate economic costs of mitigation vary widely and are highly sensitive to model design and assumptions as well as the specification of scenarios, including the characterization of technologies and the timing of mitigation (high confidence). Scenarios in which all countries of the world begin mitigation immediately, there is a single global carbon price applied, and all key technologies are available, have been used as a cost-effective benchmark for estimating macroeconomic mitigation costs (Table SPM.2, green segments). Under these assumptions, mitigation scenarios that reach atmospheric concentrations of about 450ppm CO2eq by 2100 entail losses in global consumption – not including benefits of reduced climate change as well as the co-benefits and adverse side effects of mitigation, measured as a change from baseline consumption, of 1% to 4% (median: 1.7%) in 2030, 2% to 6% (median: 3.4%) in 2050, and 3% to 11% (median 4.8%) in 2100 relative to consumption in baseline scenarios that grows anywhere from 300% to more than 900% over the century. These numbers correspond to an annualized reduction of consumption growth by 0.04 to 0.14 (median 0.06) percentage points over the century relative to annualized consumption growth in the baseline that is between 1.6 to 3% per year... Delaying mitigation further increases mitigation costs in the medium to long term (Table SPM.2, blue segment). Many models could not achieve atmospheric concentrations levels of about 450 ppm CO2eq by 2100 if additional mitigation is considerably delayed or under limited availability of key technologies – such as bioenergy, CCS and their combination (BECCS). [6.3]” [SPM. Page 17]

“Mitigation scenarios reaching about 450 or 500 ppm CO2eq by 2100 show reduced costs for achieving air quality and energy security objectives, with significant co-benefits for human health, ecosystem impacts, and sufficiency of resources and resilience of the energy system; these scenarios did not quantify other co-benefits or adverse side effects (medium confidence).” [SPM. Page 19]

14) Acting fast reduces costs and risks and avoids more drastic measures
"Infrastructure developments and long-lived products that lock societies into GHG-intensive emissions pathways may be difficult or very costly to change, reinforcing the importance of early action for ambitious mitigation (robust evidence, high agreement)." [SPM. Page 20]

“Estimated global GHG emissions levels in 2020 based on the Cancún Pledges are not consistent with cost-effective long-term mitigation trajectories that are at least as likely as not to limit temperature change to 2°C relative to preindustrial levels (2100 concentrations of about 450 and about 500 ppm CO2eq), but they do not preclude the option to meet that goal (high confidence).”[SPM. Page 15]

“Delaying mitigation efforts beyond to those in place today through 2030 is estimated to substantially increase the difficulty of the transition to low longer-term emissions levels, and narrow the range of options consistent with maintaining temperature change below 2°C relative to preindustrial levels (high confidence). [SPM, page 16]

15) Global cooperation is needed 
Chapter 6 on “Assessing Transformation Pathways“ compares effort-sharing results from different reports, under “6.3.6.6 Regional mitigation costs and effort-sharing regimes”. A comparison is presented of findings of over 40 studies on future GHG emissions allowances or reduction targets for different regions, based on a wide range of effort-sharing approaches, while noting that comparing different effort sharing models is inherently complex: 

“Comparing emission allocation schemes from these proposals is complex because studies explore different regional definitions, timescales, starting points for calculations, and measurements to assess emission allowances such as CO2 only or as CO2-e (see Höhne et al., 2013). The range of results for a selected year and concentration goal is relatively large due to the fact that it depicts fundamentally different effort-sharing approaches and other varying assumptions of the studies. Nonetheless, it is possible to provide some general comparison and characterization of these studies.” [Chapter 6, p54, section 6.3.6.6]

"The concentration goal is significant for the resulting emissions allowances (Figure 6.29). Indeed, for many regions, the concentration goal is of equal or larger importance for emission allowances than the effort-sharing approach. For concentration levels between 430 and 480 in 2100, the allowances in 2030 under all effort sharing approaches in OECD1990 are approximately half of 2010 emissions with a large range, roughly two-thirds in the Economies in Transition (EIT), roughly at the 2010 emissions level or slightly below in Asia, slightly above the 2010 level in the Middle East and Africa, and well below the 2010 level in Latin America.” [Chapter 6. Page 56]

Comments Add new comment

Sounds like a plan.

Sounds like a plan.

You actually make it seem so easy with your presentation but I find this
matter to be actually something which I think I would never understand.
It seems too complex and extremely broad for me.
I am looking forward for your next post, I will try to get
the hang of it!

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