IMPACTS of Climate Change / Global Warming  

• OVERVIEW

• IPCC Report II on Impacts, Adaptation and Vulnerability
  

• Video: Rising Temperatures and Falling Plant Growth (NASA)

• Videos: Global Warming and Extreme Weather 

OVERVIEW: 

Impacts of climate change due to the human-caused trend of global warming are now becoming evident, and these impacts will become far worse in the future if substantial mitigating action is not taken soon.  While impacts due to natural climate change have always occurred, global warming accentuates these impacts. For the earth as a whole, these extra impacts will be overwhelmingly negative. Regionally and temporally, there will be variations. The basic reason is simple - more energy due to global warming on the whole produces more impact.

While nothing will ever be 100% certain, and while attribution for many impacts can only be deduced statistically, expert opinion warns us that a variety of disasters awaits if we continue with "Business as Usual". To get an idea, think of smoking. While individual cases cannot be "proved", it is statistically irrefutable that smoking leads to a variety of horrible diseases and deaths. Prudent risk management says "don't smoke", and prudent risk management says "mitigate global warming".

Related articles on global warming impacts with references and links are on this Climate Portal. See the IPCC Impacts report below for detailed documentation.

Here is a summary list:

Water: Glaciers and snow packs that now provide water to many millions of people are melting, foreshadowing severe regional water shortages in the future. HERE are the slides of a review by Dr Peter Gleick "The Vulnerability of U.S. Water Resources to Climate Change: From the Mississippi River floods to growing shortages in the West" presented to the US House of Representatives in partnership with the American Association for the Advancement of Science (AAAS).

Food: Disruption of food supplies, agriculture, and fisheries will occur drastically for many hundreds of millions, conservatively, by 2100. Increased rain in the winter and increased evaporation in the summer in addition to pest migration will stress crops. This will lead to bad food shortages, including in the US; see HERE and the NASA VIDEO below. Global warming is negatively affecting pollination and bees, said to be responsible for 1/3 of human nutrition. HERE is an article backed by extensive data (explained HERE), showing that fish crucial for the marine food chain are in danger of decreasing by over 50% due to the extension of OMZ (oxygen minimum zones), due to global warming. Global phytoplankton, at the base of the marine food chain, is in decline due to rising sea temperature; see HERE. The earth already has 800 million people that go to bed hungry each night. Global warming will substantially increase this number.

Migration: Food and water shortages, coupled with sea level rise in costal regions, will lead to migration of many millions of displaced and desperate people.

Wars and Breakdown of Peace: Tensions between nations stressed by water and food shortages, along with migrations, will lead to more wars. There are some indications that these factors were the underlying cause of the tragic Darfur conflict. Political instability will increase. Terrorism due to desperate groups will likely increase.

Economics and Finance System Breakdown: Recent events have exhibited the fragility of the worldwide financial and economic systems. The severe environmental and political strains due to global warming impacts, coupled with the mass psychological effects of fear, may well severely effect financial and economic stability worldwide. This includes Europe and the United States.

Disease: As warming occurs, disease vectors including insects move north. This will increasingly affect the disease transmission to people, crops, and forests in many regions.

Oceans: "Fundamental and comprehensive" changes to marine life include rapidly warming and acidifying oceans, changes in water circulation and expansion of dead zones within the ocean depths. According to the National Security Implications of Climate Change for U.S. Naval Forces (2011): RECOMMENDATION 3.1: Based on recent peer-reviewed scientific literature, the Department of the Navy should expect roughly 0.4 to 2 meters global average sea-level rise by 2100, with a most likely value of about 0.8 meter. Projections of local sea-level rise could be much larger and should be taken into account for naval planning purposes.

Droughts: As warming occurs, more evaporation occurs, causing more regional droughts.

Fires: As warming occurs, more precipitation causes more underbrush to grow, which dries during the summer, providing tinder for wildfires. For example, note the recent increases in California fires and Arizona/New Mexico fires, the worst since the last Ice Age (picture below):

Hurricanes: Although there are competing factors, there is evidence that global warming may well be increasing the strength of the largest hurricanes.

Sea Level Rise and ice: Recent evidence shows that glaciers in Antarctica are disintegrating at a faster rate than before, due to complex ice dynamics. If these glaciers disintegrate or slide into the ocean from the land, sea level rise will be measured in meters, and will affect hundreds of millions of people. Coastal regions in many parts of the world will be flooded. Time scales for such effects are being substantially revised from the previous IPCC estimates (which mentioned but did not quantitatively include these effects) to shorter times.

Failed States: This is increasingly being mentioned as a distinct possibility for some underdeveloped countries stressed by global warming effects without sufficient resources to adapt.

Extinctions: Many species (animals and plants) will become extinct.  HERE is a summary and HERE is a great video. An article on University of Exeter research gives the estimate that one in 10 species could face extinction by the year 2100 if current climate change impacts continue.

Extreme Weather: More energy in the atmosphere due to global warming means more energy is available to produce more extreme weather events. See the videos below.

OTHER: There are many more potential impacts of global warming. For a detailed discussion, please see the 2007 Impacts, Adaptation, and Vulnerability IPCC Report (Vol II), outline BELOW.

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IPCC Report: Climate Change 2007

Impacts, Adaptation and Vulnerability

Contents

• Introduction to the Report

• Summary for Policymakers

• Technical Summary

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• Chapter 1: Assessment of Observed Changes and Responses in Natural and Managed Systems - [ Supplementary Material ]

• Chapter 2: New Assesment Methods and the Characterisation of Future Conditions

• Chapter 3: Fresh Water Resources and their Management

• Chapter 4: Ecosystems, their Properties, Goods and Services

• Chapter 5: Food, Fibre, and Forest Products

• Chapter 6: Coastal Systems and Low-Lying Areas

• Chapter 7: Industry, Settlement and Society

• Chapter 8: Human Health

• Chapter 9: Africa

• Chapter 10: Asia

• Chapter 11: Australia and New Zealand

• Chapter 12: Europe

• Chapter 13: Latin America

• Chapter 14: North America

• Chapter 15: Polar Regions (Arctic and Antarctic)

• Chapter 16: Small Islands

• Chapter 17: Assessment of Adaptation Practices, Options, Constraints and Capacity

• Chapter 18: Inter-Relationships Between Adaptation and Mitigation - [ Supplementary Material ]

• Chapter 19: Assessing Key Vulnerabilities and the Risk from Climate Change

• Chapter 20: Perspectives on Climate Change and Sustainability

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Cross-Chapter Case Studies 

Appendices I-V: Glossary, Contributors, Reviewers, Acronyms, Permissions

Index

Errata for Working Group II Fourth Assesment Report

Figures

Statements on issues raised since the release of the AR4

Cambridge University Press, Cambridge, UK, 976 pp

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VIDEO: Rising Temperatures and Falling Plant Growth (NASA)

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VIDEOS: Extreme Weather Events and Global Warming

This is Not Cool. Heatwave 2011

Prof. Scott Mandia

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