Chapter 11

• Climate change is a broad range of global phenomena created predominantly by burning fossil fuels, which add heat-trapping gases to Earth’s atmosphere.
• hese phenomena include the increased temperature trends described by global warming, but also encompass changes such as sea level rise, ice mass loss, shifts in flower/plant blooming and extreme weather events
• causes of climate change: greenhouse gas emissions, earth's natural climate cycle, solar influences
• Greenhouse gas emissions Evidence that CO2 emissions are the cause of global warming is very robust. Scientists have known since the early 1800s that greenhouse gases in the atmosphere trap heat. Global CO2 emissions from human activity have increased by over 400% since 1960. As a result, the concentration of CO2 in the air has reached more than 400 parts per million by volume (ppm), compared to about 280 ppm in 1750 (around the start of the Industrial Revolution).
• Earth’s natural climate cycle Over the last 800,000 years, there have been natural cycles in the Earth’s climate, between ice ages and warmer interglacial periods. After the last ice age 20,000 years ago, average global temperature rose by about 3°C to 8°C, over a period of about 10, 000 years
• Solar influences The sun is the primary source of Earth’s heat, so relatively small changes in solar output can affect our climate. Satellite observations since the late 1970s have shown a slight decrease in the sun’s total energy output. However, instead of cooling, the Earth has warmed over this period.
• impacts on vulnerability and equity: geographic location, ability to cope, indigenous people, urban people, impacts on economic activities and services
• Population in coastal areas are more sensitive to storms, drought, air pollution and heat waves.
• Population in mountainous areas will likely face water shortages and increased wildfires in the future.
• Arctic residents will likely experience problems caused by thawing permafrost
• Young children are another sensitive age group, since their immune system and other bodily systems are still developing and they rely on others to care for them in disaster situations.
• People who live in poverty may have a difficult time coping with changes. These people have limited financial resources to cope with heat, relocate or evacuate, or respond to increases in the cost of food.
• Climate change will make it harder for tribes to access safe and nutritious food, including traditional foods important to many tribes’ cultural practices
• City residents and urban infrastructure have distinct sensitivities to climate change impacts. For example, heat waves may be amplified in cities because cities absorb more heat during the day than suburban and rural areas. Cities are more densely populated than suburban or rural areas. As a result, increases in heat waves, drought, or violent storms in cities would affect a larger number of people than in suburban or rural areas.
• In 1992, the United Nations Framework Convention on Climate Change (UNFCC) was adopted as the basis for a global response to the problem.
• The Philippines signed the UNFCCC on 12 June 1992 and ratified the international treaty on 2 August 1994
• Presently, the Convention enjoys near universal membership with 194 Country Parties.
• Countries are actively discussing and negotiating ways to deal with the climate change problem within the UNFCCC using two central approaches.: 1. To address the root cause by reducing greenhouse gas emissions from human activity 2. Manage its impacts
• Taking steps to cope with the changed climate conditions both in terms of reducing adverse impacts and taking advantage of potential benefits is called adaptation.
• Observations show that the stratosphere is in fact cooling while the troposphere warms.