Changes

Approximately 40 percent of the global population live within 100km (60 miles) of the coast. Around 10 percent of the world’s population live in coastal areas that are less than 10 meters above sea level<ref>[https://www.un.org/sustainabledevelopment/wp-content/uploads/2017/05/Ocean-fact-sheet-package.pdf UN]</ref>. As a result of climate change, sea levels are rising, the ocean is warming and seawater is becoming more acidic due to carbon dioxide intake. Even if warming is kept well below 2°C, there is a high confidence that communities in all regions of the world – especially coastal communities – will still have to adapt to these changes in the world’s oceans<ref>[https://www.ipcc.ch/srocc/ IPCC 2019 Special Report The Ocean and Cryosphere in a Changing Climate]</ref>.

Approximately 40 percent of the global population live within 100km (60 miles) of the coast. Around 10 percent of the world’s population live in coastal areas that are less than 10 meters above sea level<ref>[https://www.un.org/sustainabledevelopment/wp-content/uploads/2017/05/Ocean-fact-sheet-package.pdf UN]</ref>. As a result of climate change, sea levels are rising, the ocean is warming and seawater is becoming more acidic due to carbon dioxide intake. Even if warming is kept well below 2°C, there is a high confidence that communities in all regions of the world – especially coastal communities – will still have to adapt to these changes in the world’s oceans<ref name=":21">[https://www.ipcc.ch/srocc/ IPCC 2019 Special Report The Ocean and Cryosphere in a Changing Climate]</ref>.

Living with climate change means living with uncertainty<ref>[https://gar.undrr.org/sites/default/files/gar19distilled.pdf 2019 Global Assessment Report on Disaster Risk Reduction]</ref>. One of these uncertainties is around the idea of a “tipping point”.  

Living with climate change means living with uncertainty<ref name=":22">[https://gar.undrr.org/sites/default/files/gar19distilled.pdf 2019 Global Assessment Report on Disaster Risk Reduction]</ref>. One of these uncertainties is around the idea of a “tipping point”.  

The IPCC introduced the idea of tipping points two decades ago. A possible tipping point is the melting of land ice in the polar regions (Greenland and Antarctica), leading to many meters of sea-level rise over time. Models suggest that the '''Greenland ice sheet''' could eventually disappear at 1.5 °C of warming<ref name=":8" />^{^]}, although only after many years. In July 2021, a heat wave caused Greenland to lose enough ice to cover the US state of Florida in 2 inches (5cm) of water in one day<ref>"[https://www.reuters.com/world/europe/greenland-experienced-massive-ice-melt-this-week-scientists-say-2021-07-30/ Greenland experienced 'massive' ice melt this week, scientists say.]” Reuters</ref> ^{^[5]}. Sea ice is already shrinking rapidly in the Arctic, indicating that, at 2°C of warming, the region has a 10–35 percent chance of becoming largely ice-free in the summer^{^[6]}.

The IPCC introduced the idea of tipping points two decades ago. A possible tipping point is the melting of land ice in the polar regions (Greenland and Antarctica), leading to many meters of sea-level rise over time. Models suggest that the '''Greenland ice sheet''' could eventually disappear at 1.5 °C of warming<ref name=":8" />^{^]}, although only after many years. In July 2021, a heat wave caused Greenland to lose enough ice to cover the US state of Florida in 2 inches (5cm) of water in one day<ref>"[https://www.reuters.com/world/europe/greenland-experienced-massive-ice-melt-this-week-scientists-say-2021-07-30/ Greenland experienced 'massive' ice melt this week, scientists say.]” Reuters</ref> <ref name=":21" />. Sea ice is already shrinking rapidly in the Arctic, indicating that, at 2°C of warming, the region has a 10–35 percent chance of becoming largely ice-free in the summer<ref>[https://www.ipcc.ch/srocc/chapter/chapter-3-2/ IPCC Special Report on Polar Regions]</ref>.

Another possible tipping point is the large-scale destruction of rainforests like the Amazon, which is home to one in 10known land-based species. Estimates of where an Amazon tipping point could lie range from 40 percent deforestation to just 20 percent forest-cover loss. About 17 percent has been lost since 1970^{^[7]}, with more being lost due to human deforestation every minute.  

Another possible tipping point is the large-scale destruction of rainforests like the Amazon, which is home to one in 10known land-based species. Estimates of where an Amazon tipping point could lie range from 40 percent deforestation to just 20 percent forest-cover loss. About 17 percent has been lost since 1970<ref name=":8" />, with more being lost due to human deforestation every minute.  

^{^[2]} Lenton. Climate Tipping Points too Risky to Bet Against

An example of this can be found in the Arctic. The greenhouse gas methane is currently “stored” in Arctic permafrost. As global warming causes the permafrost to melt, the methane stored is released into the atmosphere, adding yet more greenhouse gas emissions that can lead to further global warming. More warming results in more melting permafrost, adding yet more methane to the atmosphere to create even more warming and more melting permafrost, and on and on. These feedback loops are non-linear, meaning they can’t be predicted with any certainty and could arise in a way that science has not predicted<ref name=":22" />.  

^{^[4]} “Greenland experienced 'massive' ice melt this week, scientists say.” Reuters

The next 10 years will be critical for adapting to and mitigating climate change. Being well informed about the risks and causes of climate change helps us to make the best decisions in the present, but it is still not possible to predict the future with 100 percent certainty. Climate change is happening much faster than efforts to address it, and the past is not a reliable indicator of the future<ref name=":22" />. Going forward, the future is uncertain. This understanding creates discomfort (a sense of things being out of control), but also opportunity<ref name=":22" />. There is still time to avert the crisis, if action is taken now.

^{^[5]} IPCC Special Report on the Ocean and Cryosphere in a Changing Climate.

[[File:Information Booklet Climate tipping elements.png|alt=Figure 2: Climate tipping elements that could cross this century due to human activities (from Lenton et. al., 2019, Nature)|center|thumb|596x596px|Figure 2: Climate tipping elements that could cross this century due to human activities (from Lenton et. al., 2019, Nature)]]

^{^[6]} IPCC Special Report on Polar Regions

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^{^[7]} Lenton. Climate Tipping Points too Risky to Bet Against

'''''It’s been six years since the Paris Agreement. What action has been taken by countries so far to reduce emissions and biodiversity loss, and what more needs to be done?'''''

----^{^[1]} UNEP 2021 Making Peace with Nature, pg.16

=== <big>Energy transition</big> ===

One of the most important actions of the next decade will be to switch electricity generation to renewable sources and away from fossil fuels. So far, the increasing availability of renewable energy has not displaced fossil fuels, but instead contributed to a growth in total energy use<ref>[https://www.annualreviews.org/doi/pdf/10.1146/annurev-environ-012220-011104#article-denial Three Decades of Climate Mitigation: Why Haven't We Bent the Global Emissions Curve?]</ref>.

^{^[3]} IPBES 2019 Global Assessment

Universal access to clean and affordable energy requires a transformation of both the production and use of energy<ref name=":11" />. To reduce coal use by 70 percent by 2030 means a five-fold increase in wind and solar energy, as well as phasing out and closing 2,400 coal-fired power stations globally within the next decade<ref name=":9" />. Facilitating the transition to replace fossil-fuel energy with renewable energy will be expensive, but it is much cheaper to mitigate climate change than to adapt to climate change<ref>Burke et al, [https://www.nature.com/articles/s41586-018-0071-9/ Large potential reduction in economic damages under UN mitigation targets]</ref>.

^{^[5]} UN

Additionally, there are multiple economic and health benefits from transitioning to a low-carbon economy, such as a reduction in urban air pollution<ref>[https://wedocs.unep.org/xmlui/bitstream/handle/20.500.11822/34949/MPN_ESEN.pdf UNEP 2021, Making Peace with Nature], Section 4.1</ref> <ref>[https://www.ipcc.ch/sr15/ IPCC 2018 Global Warming of 1.5oC], Chapter 3, section 5.2</ref> <ref>[https://www.unep.org/resources/global-environment-outlook-6 Global Environmental Outlook 6 2019], Key Message 19, Chapter 24.4, and Box 24.1</ref>.

^{^[7]} IPCC 2019 Special Report The Ocean and Cryosphere in a Changing Climate, SPM A4, A5 & A6

Solar and wind energy are now cheaper than coal or gas-fired plants in most countries, and solar projects offer some of the lowest cost electricity ever seen<ref>[https://www.iea.org/reports/world-energy-outlook-2020 International Energy Agency 2020 World Energy Outlook Executive Summary]</ref>. However, the increasing availability of renewable energy has so far just increased the global demand for energy, not replaced energy created from fossil fuels<ref name=":10" />.

----^{^[1]} WHO Ecosystems and Human Wellbeing

The early retirement or repurposing of energy infrastructure is necessary to meet Paris commitments. Many studies show that simply allowing existing fossil fuel facilities to run until their expected end of life would not keep emissions below both 1.5°C and 2°C<ref name=":10" />.

 

^{^[4]} UNEP 2021, Making Peace with Nature, SPM Section 3.2

 

 

^{^[6]} UNEP 2021 Making Peace with Nature, pg.71

 

 

 

^{^[9]} IPCC Chapter 2: Land-climate interactions

 

^{^[10]} UNEP 2021 Making Peace with Nature, pg.71

 

^{^[11]} UNEP 2021 Making Peace with Nature, pg.16