Answers – Climate Change & Greenhouse Gases

Answer: Climate is the average weather pattern in a place over a long period (usually at least 30 years). It includes average temperature, rainfall, humidity, wind patterns, and seasonal changes. Weather, in contrast, refers to the short-term conditions we experience day to day. While weather can change from day to day or hour to hour, climate changes much more slowly over decades or centuries.

Answer: Climate change refers to significant changes in average weather patterns that last for an extended period – decades or longer. It can be detected by:

• Rising average global temperatures over time
• Changes in rainfall patterns (some regions becoming wetter, others drier)
• Increased frequency and intensity of extreme weather events (storms, floods, droughts)
• Rising sea levels due to melting ice and thermal expansion of ocean water
• Changes in the timing of seasons (earlier spring arrival, shorter winters)

Answer: Natural causes of climate change include:

• Volcanic eruptions – large eruptions release dust and gases that can block sunlight and temporarily cool the Earth
• Changes in the sun’s energy output – variations in solar radiation affect Earth’s climate
• Earth’s orbital changes – variations in Earth’s orbit affect how much solar energy reaches different parts of Earth

Human causes of climate change include:

• Burning fossil fuels (coal, oil, natural gas) – releases carbon dioxide
• Deforestation – reduces the number of trees that absorb carbon dioxide
• Industrial processes – releasing greenhouse gases such as methane, nitrous oxide, and fluorinated gases
• Agriculture – rice farming and livestock raising release methane

Answer: Adaptation refers to adjusting to the effects of climate change that are already happening or will happen. For example, building sea walls to protect coastal areas from rising sea levels.

Mitigation refers to reducing or preventing greenhouse gas emissions to slow or stop climate change. For example, switching from fossil fuels to renewable energy sources like solar or wind power.

The key difference is that adaptation deals with the consequences of climate change, while mitigation addresses the causes to prevent further climate change.

Answer: Greenhouse gases are gases in Earth’s atmosphere that trap heat. They are called “greenhouse” gases because they work similarly to the glass in a greenhouse – they allow sunlight to pass through the atmosphere and reach Earth’s surface, but they prevent some of the heat that radiates back from Earth from escaping into space. Just as a greenhouse stays warm because the glass traps heat inside, these gases trap heat in Earth’s atmosphere, keeping our planet warmer than it would be without them.

Answer: The greenhouse effect is a natural process that warms Earth’s surface. It works as follows:

1. The sun’s energy reaches Earth as sunlight (shortwave radiation)
2. Some of this energy is absorbed by the Earth’s surface and warms it
3. The Earth’s surface releases heat back into the atmosphere (longwave radiation)
4. Greenhouse gases in the atmosphere trap some of this heat
5. This trapped heat keeps Earth warm enough to support life

Without the natural greenhouse effect, Earth’s average temperature would be about -18°C (0°F) instead of the current average of about 15°C (59°F), making the planet too cold for most life forms. The problem occurs when human activities increase the concentration of greenhouse gases, enhancing this effect and causing excessive warming.

Answer: Global warming refers specifically to the long-term increase in Earth’s average surface temperature due to rising levels of greenhouse gases from human activities. It is actually one aspect of climate change, which includes not only warming but also changes in precipitation patterns, sea levels, and the frequency and intensity of extreme weather events.

Global warming is the direct result of the enhanced greenhouse effect, where human-produced greenhouse gases trap more heat in the atmosphere. While global warming refers to the temperature increase itself, climate change encompasses all the wider environmental effects that result from this warming. In simpler terms, global warming is the cause, and climate change includes all the effects.

Answer: Three main greenhouse gases are:

• Carbon dioxide (CO₂):
  • Natural source: Respiration (breathing) of animals and plants
  • Human source: Burning fossil fuels like coal, oil, and natural gas
• Methane (CH₄):
  • Natural source: Wetlands where bacteria decompose organic matter
  • Human source: Livestock farming (cattle burping and manure) and rice paddies
• Nitrous oxide (N₂O):
  • Natural source: Soil bacteria and oceans
  • Human source: Agricultural fertilizers and industrial processes

Answer: Deforestation contributes to climate change in several ways:

• Carbon release: Trees store carbon dioxide as they grow. When forests are cut down and burned or left to rot, this stored carbon is released back into the atmosphere as CO₂, adding to greenhouse gas concentrations.
• Reduced carbon absorption: Forests act as “carbon sinks,” absorbing CO₂ from the atmosphere. When forests are removed, this important function is lost. The Amazon rainforest alone absorbs about 2 billion tons of CO₂ annually.
• Local climate changes: Forests help regulate local climate by influencing rainfall patterns, humidity, and temperature. Deforestation in the Amazon has been linked to reduced rainfall in the region and increased temperatures.
• Soil degradation: Removing trees can lead to soil erosion, which reduces the ability of the land to store carbon.

For example, in Indonesia, clearing forests for palm oil plantations has made the country one of the world’s largest emitters of greenhouse gases, despite having a smaller industrial sector than many developed nations.

Answer: Three effects of global warming already being observed around the world include:

• Rising sea levels: Global sea levels have risen about 8-9 inches since 1880, with about a third of that occurring in the last 25 years. This is causing increased coastal flooding, erosion, and saltwater intrusion into freshwater systems. Cities like Venice, Italy and Miami, Florida are experiencing more frequent flooding events.
• Extreme weather events: There has been an increase in the frequency and intensity of extreme weather events such as hurricanes, heatwaves, and droughts. For example, Hurricane Harvey in 2017 was made more intense by warmer ocean temperatures, and record-breaking heatwaves have become more common across Europe and North America.
• Loss of ice and snow cover: Arctic sea ice is declining at a rate of about 13% per decade. Mountain glaciers are retreating worldwide, including in the Alps, Himalayas, Andes, and Alaska. The Greenland and Antarctic ice sheets are losing mass at an accelerating rate, contributing to sea level rise.

Answer: Two adaptation strategies for a small island nation facing rising sea levels are:

• Building coastal defenses: They could construct sea walls, breakwaters, or surge barriers to protect coastal villages from rising waters and storm surges. For example, the Maldives has built a 3-meter high wall around its capital, Malé, and artificial islands like Hulhumalé with higher elevations to protect against sea level rise.
• Managed retreat: They could develop plans to gradually relocate people and infrastructure from low-lying coastal areas to higher ground. Fiji has already begun relocating coastal communities to higher elevations, with over 40 villages identified for relocation due to sea level rise.
• Ecosystem-based adaptation: They could restore and protect natural coastal ecosystems like mangroves, coral reefs, and wetlands that provide natural barriers against waves and erosion. Countries like Tuvalu are working to protect and restore their coral reef systems to act as natural breakwaters.

Answer: Methane from livestock farming is considered a significant greenhouse gas despite being released in smaller quantities than carbon dioxide for several important reasons:

• Higher warming potential: Methane is much more potent at trapping heat than carbon dioxide. Over a 20-year period, methane is about 84-86 times more effective at trapping heat in the atmosphere than CO₂, and over a 100-year period, it’s still about 28-34 times more potent. This means even smaller quantities have a large impact.
• Concentration growth: Atmospheric methane concentrations have more than doubled since pre-industrial times, largely due to human activities including livestock farming.
• Scale of livestock production: There are approximately 1.5 billion cattle worldwide, each producing significant amounts of methane through their digestive process (enteric fermentation) and from their manure. As global meat consumption increases, so does this source of methane.

This is why reducing methane emissions from livestock through improved farming practices, feed additives, or dietary shifts can have a significant and relatively rapid impact on slowing climate change.

Answer: Three ways individuals can help mitigate climate change in their daily lives:

• Reduce energy use: Turn off lights and appliances when not in use, use energy-efficient appliances, improve home insulation, adjust thermostat settings (lower in winter, higher in summer), and switch to energy-efficient LED lighting. This reduces the amount of fossil fuels needed to generate electricity.
• Change transportation habits: Walk, cycle, or use public transportation instead of driving; carpool when possible; combine errands to reduce trips; consider an electric or hybrid vehicle for your next car purchase. Transportation is a major source of greenhouse gas emissions in many countries.
• Adjust diet and food choices: Reduce consumption of meat, especially beef, which has a high carbon footprint; buy locally produced, seasonal foods to reduce transportation emissions; reduce food waste by planning meals, storing food properly, and composting; grow some of your own food if possible.
• Other impactful actions: Reduce, reuse, and recycle to minimize waste; choose products with less packaging; support companies with strong climate commitments; participate in community climate initiatives; talk to others about climate change to raise awareness.

Answer: Three adaptation measures a city experiencing more frequent heat waves could implement to protect its residents:

• Urban greening: Increase vegetation in the city by creating more parks, green roofs, and street trees. Plants provide natural cooling through shade and evapotranspiration, reducing the urban heat island effect. Cities like Singapore have increased their green cover from 36% to 47% and plan to plant a million more trees by 2030.
• Cool infrastructure: Use reflective materials for roofs, walls, and pavements that absorb less heat. Install water features like fountains and misting systems in public spaces. Los Angeles has implemented a cool pavement program, painting streets with light-colored coating that reflects sunlight and reduces surface temperatures by up to 10°F.
• Public cooling centers and warning systems: Establish air-conditioned public facilities where people can go during extreme heat, especially for vulnerable populations like the elderly. Develop early warning systems to alert residents about upcoming heat waves and provide guidance on how to stay safe. Paris created a heat wave plan after the deadly 2003 heatwave, which includes checking on elderly residents and opening cooling centers.

Answer: Comparing the roles of developed and developing countries in causing and addressing climate change:

• Historical responsibility: Developed countries have contributed most to the accumulated greenhouse gases in the atmosphere due to their earlier industrialization and higher historical emissions. The United States and European countries are responsible for about 50% of cumulative CO₂ emissions since 1850, despite having a smaller share of the global population.
• Current emissions: While developed countries still have higher per capita emissions, many developing countries now have higher total emissions due to their larger populations and rapid industrialization. China is currently the world’s largest emitter, though its per capita emissions are still lower than many developed nations.
• Capacity to respond: Developed countries generally have more financial resources, technology, and infrastructure to implement climate solutions. They can afford to invest in renewable energy, research and development, and adaptation measures.
• Development priorities: Developing countries often face competing priorities between economic development (including poverty reduction) and climate action. They argue for their right to develop as developed countries did, while developed nations push for cleaner development pathways.
• International agreements: Climate agreements like the Paris Agreement recognize these differences through “common but differentiated responsibilities,” where developed countries are expected to take the lead in cutting emissions and providing financial and technological support to developing countries.

The challenge is to find approaches that allow developing countries to improve living standards while avoiding the high-emission development path that developed countries took, supported by technology transfer and financial assistance from developed nations who bear greater historical responsibility.