Climate Change



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What does climate change mean to you? How much do you know or understand about this term? Though many scientists and environmentalists have warned the world of the potential danger and irreversible consequences of climate change, such as the increasingly rapid retreat of glaciers, most people still pay little attention or simply don’t care enough to adjust the way they live to protect the earth, especially those living in areas where no imminent climate impacts and risks have been felt, yet.

Although there are different opinions and attitudes held towards climate change, one indisputable fact is that eventually, every person will be affected and no one can escape from it. It is only a matter of when and how hard it will hit you. Therefore, it will be wise for us to learn more about this topic and see what we can do to save our earth and live more sustainably!

What

According to the United Nations Framework Convention on Climate Change (UNFCCC), climate change refers to a change of climate that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and that is in addition to natural climate variability observed over comparable time period.

Climate change: how do we know?

  1. Sea level rise

    2. The two major causes of global sea level rise are thermal expansion of the oceans (water expands as it warms) and additional water flows into the oceans from ice that melts on land.

    The rise has happened more rapidly in the past few decades. According to NASA, the rate of rise in 2024 was 5.9 mm per year, which was 1.6 mm higher than expected. In total, the global sea level has gone up by 10 cm since 1993.

  2. Global warming

    3. Global warming refers to the rise of the average temperatures on Earth’s surface, oceans and atmosphere. According to NASA’s Goddard Institute for Space Studies (GISS), the average surface temperature in 2024 was the warmest on record since 1880. Earth was about 1.47 °C warmer in 2024 than in the preindustrial period (1850-1900) average. In fact, the 10 most recent years are the hottest on record.

  3. Extreme weather events

    4. Climate change has greatly increased the intensity, frequency and impacts of severe weather events, such as storms, flooding, heat waves and droughts. For example, sea level rise increases the impact of coastal storms, while global warming can aggravate droughts. These events are posing great threats to humans.

Impact

1. Global impact

A. Extreme weather events

    • Floods
      The total sea level keeps rising each year, which has already caused a sharp increase in flooding along coasts. Besides, more moisture is held when the atmosphere gets warmer, leading to more rainfall and larger flooding events.

    • Droughts
      Increased temperatures enhance evaporation from soils, aggravating periodic droughts, especially in the subtropics where most of the world’s deserts are located.

    • Heat waves
      The average annual temperatures favourable for human health and food production are 15 – 20s°C. Rising temperatures and humidity levels have combined to increase the intensity and frequency of heat waves. Now, around 13% of land area and 30% of the world’s population are already affected by climatic conditions of dangerous extreme heat (29°C+) and humidity surpassing a deadly threshold for at least 20 days a year.

    • Tropical cyclones
      Cyclones require warm sea water, so they are mostly formed in the tropics. Heating the ocean provides more source of energy for the cyclones and intensifies them, allowing them to cause greater damage than in the past.

B. Food insecurity

    Since agriculture is essential to the food supply, and provides livelihoods for almost two-thirds of the world’s extremely poor, the impacts of climate change on agriculture directly affect already vulnerable rural populations and their food security. Many societies depend on specific crops for food, clothing and trade. If the temperatures exceed a crop’s optimal level, or if water and nutrients are insufficient, yields are likely to fall. An increased frequency of extreme events also harms crops. People may no longer be able to grow the crops they depend on for survival. Massive internal displacement in the context of drought and food insecurity is already happening worldwide. In Africa, 6.3 million internal displacements triggered by floods and droughts were recorded across the continent in 2023 (ReliefWeb, 2024).

C. Ecological calamity

    Climate warming threatened animals in a range of areas: reduced feed intake, lower rates of reproduction and higher mortality rates. Rising temperatures also lower animals’ resistance to pathogens and parasites. Many bird populations already declined, sea corals stopped growing. Drastic changes to habitats have caused some animals to extinct, while others increase, creating imbalances that can potentially lead to ecological calamities.

    In 2016, scientists declared the extinction of the Bramble Cay melomys. This is the first documented case of a mammal being driven to extinction by climate change.

D. Human health under threat

    Direct and indirect impacts of climate change threaten humans by affecting some of the fundamental determinants of health – weather, air, water and food as well as the transmission patterns of different diseases. Warming the earth makes more people struggle with heat-related health issues, such as heat cramps, heat exhaustion, and heat strokes. Extreme high temperatures can also worsen chronic conditions such as cardiovascular and respiratory diseases. Mosquitoes which transmit vector-borne diseases, such as malaria, dengue fever, and Japanese encephalitis, are particularly active in warmer temperatures and humid conditions.

E. Exacerbating children’s vulnerability

    Currently, more than 1 billion children and adolescents under the age of 25 around the world live in areas that directly depend on land and natural resources for their livelihoods.The increasingly severe problems of climate change and land degradation have made them suffer from food insecurity, harvest failures and food price fluctuations. Although children are the least responsible for climate crisis, they directly suffer from the long-term impacts on food and nutrition, water and sanitation, disease, immunity, as well as physical and mental development.

2. Climate change in Hong Kong

Hong Kong has been called the “fortunate land” (福地) because in the past 50 years or so, we have not experienced any natural disaster that resulted in widespread casualties and damages.

However, does it mean we are free from the impacts of climate change and global warming?

In fact, climate change has been happening more rapidly in the past few decades, even without us noticing. Rising temperatures mean sea levels rise and more extreme weather events, including heavy rainfall and strong typhoons, have been observed in Hong Kong. You can find more relevant information and statistics from the Hong Kong Observatory’s website.

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3. Intensity of impact is increasing when converging with the occurrence of El Niño

El Niño, the phenomenon

About 400 years ago, El Niño phenomenon was first recognised by a group of fishermen in Latin America when they experienced unusually warm water in the Pacific Ocean. El Niño is a warming of the central to eastern Pacific Ocean, raising sea surface temperatures by 0.5-1.5°C or more, that occurs every two to seven years, and usually last 9 to 12 months.

El Niño affects weather conditions where some places experience increased rainfall while others experience drought, leading to extreme weather around the globe. The frequency and intensity of El Niño have increased by global warming caused by greenhouse-gas emissions in recent years.

What is the impact of El Niño?

Here is how El Niño is affecting different regions of the world:

  • Asia Pacific Region: Droughts and forest fires
  • Latin America: Flash floods cause decreases in fishery and crop failures
  • Africa: Droughts and erratic rainfall lead to crop failures and food shortages. Africa is the region that can least afford the impact of El Niño and faces the most extreme risk
  • Find out more about impact of El Niño on food security.

Why

  1. Greenhouse effect enhanced

    2. Greenhouse gases

    Greenhouse gases naturally exist and they are essential to the survival of humans and all living things. Greenhouse gases include carbon dioxide (CO2), methane, nitrous oxide (N2O), fluorinated gases and ozone.

    Animals and plants release carbon dioxide when they respire, or breathe. Methane is released naturally from some low-oxygen environments, such as swamps. Volcanoes — both on land and under the ocean— release greenhouse gases.

    Greenhouse effect

    When sun’s light shine onto the Earth’s surface, greenhouse gases trap some of the heat, keeping the warmth from reflecting back into space. In this way, they act like the glass walls of a greenhouse. This greenhouse effect keeps the Earth warm enough to sustain life. Scientists say that without the greenhouse effect, the average temperature of the Earth would drop from 14˚C to as low as –18˚C. However, the increase of other greenhouse gases has led to an excess of heat and energy, causing global temperatures to rise.



  2. Human activities that lead to the increase of greenhouse gases emission

    3. Increased burning of fossil fuels

    The greenhouse gases act like a blanket that keeps the earth warm and shields it from the cold of universe. They trap a good amount of heat required for life on earth. However, too much of a good thing can have a negative impact. Human activities on earth are changing the delicate balance of this natural greenhouse. As humans try to satisfy the endless hunger for energy through the unlimited burning of fossil fuels, the concentration of atmospheric carbon dioxide has increased by a third since the Industrial Revolution began. Cars, trains, airplanes, and most power plants emit huge amounts of carbon dioxide every day.

    Increasing deforestation

    Forests covers 31% of our planet. However, a record of 2024 reveals that 6.7 million hectares of tree cover in primary rainforest was lost – that is nearly the size of 60 Hong Kong. That rate of loss is equivalent to about 18 football fields disappearing every minute (World Resources Institute, 2025). Trees play a critical role in absorbing greenhouse gases, like carbon dioxide, preventing them from accumulating in the atmosphere and warming our earth. When we cut down trees, they release all the carbon they have been storing into the atmosphere. Deforestation on its own causes over 10% of worldwide greenhouse gases emissions.

    People cut down forests for different reasons, which include urbanisation, agriculture, logging operations and change of land use.

How We Help

Global perspective

Sustainable Development Goals (SDGs)

At the United Nations Sustainable Development Summit on 25 September 2015, world leaders adopted the 2030 Agenda for Sustainable Development, which includes a set of 17 Sustainable Development Goals (SDGs) to end poverty, fight inequality and injustice, and tackle climate change by 2030 (UNDP 2015).

Goal 13 of SDGs urges us to “take urgent action to combat climate change and its impacts”, which is a direct response to the issue of climate change.

Summary of Goal 13: Climate Action

  • Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries
  • Integrate climate change measures into national policies, strategies and planning
  • Improve education, awareness-raising and international capacity on climate change mitigation, adaptation, impact reduction and early warning
  • Implement the commitment undertaken by developed-country parties to the United Nations Framework Convention on Climate Change to address the needs of developing countries in the context of meaningful mitigation actions and transparency on implementation
  • Strengthen capacity for effective planning and management in least developed countries and small islands, including focusing on women, youth and local and marginalised communities

What World Vision is doing

World Vision works with vulnerable communities to increase their resilience to climate change, as well as providing assistance when disasters occur. Our approaches include mitigation, adaptation and disaster relief.

  1. Mitigation: Avoid the unmanageable

    This approach involves reducing carbon dioxide gas emissions and stopping the problem of climate change from growing. This means burning less fossil fuel (coal, oil and natural gas) and introducing clean energy and energy-efficient approaches.

    Another way to reduce carbon dioxide in the atmosphere is reforestation and the conservation of existing forests that helps absorbing carbon dioxide, a major greenhouse gas, in the atmosphere.

    Farmer Managed Natural Regeneration (FMNR) is a low-cost land restoration technique used to combat poverty and hunger amongst poor subsistence farmers by increasing food and timber production and resilience to climate extremes. In practice, FMNR involves the systematic regrowth and management of trees and shrubs from felled tree stumps, sprouting root systems or seeds. The regrown trees and shrubs – integrated into crops and grazing pastures – help restore soil structure and fertility, inhibit erosion and soil moisture evaporation, rehabilitate springs and the water table, and increase biodiversity. Some tree species also impart nutrients such as nitrogen into the soil.

  2. Adaptation: Manage the unavoidable

    Adaptation involves learning how to live with existing climate change and protecting ourselves from the future effects of climate change. For example, this includes farmers growing drought resistant crops and learning new ways in ‘climate-smart’ agricultural interventions and sustainable land management practices.

    World Vision Australia has a dedicated Food Security and Climate Change team that develops and oversees a pipeline of global development projects with communities, governments and world-class partners across Africa, South America, South Asia and the Pacific region.

  3. Disaster response

    In response to extreme weather events, World Vision acts: before, during and after disasters strike. To be able to help communities affected by disasters, World Vision needs to ensure community readiness before the emergency. Most regions where World Vision works maintain their own stockpiles of relief items, such as tarpaulins, household kits and water carriers, plus reliable access to emergency food supplies. In addition to this, World Vision’s strategically located disaster response warehouses are pre-stocked with relief supplies, allowing the organisation to ship vital aid supplies – water purification tablets, shelter materials, cooking utensils and blankets, for example – without delay.

    Disaster teams in each country work with communities on disaster preparedness, including risk recognition, evacuations and early warning systems. Click here for more updates and details of our relief work.

How can you respond?

Adjust your lifestyle to minimise carbon emission

WEAR low carbon：Purchase durable clothes. Buy only what you need and what you will wear for years. Remember that producing new clothes consumes energy and resources.

EAT low carbon： Eating more vegetable and less red meat is good for both your health and the environment. Choose seasonal food and support local produce will also help reduce energy consumption and carbon emission due to shorter transport distance. In addition, excessive chemicals and packaging can be avoided with simple fresh keeping procedures.

LIVE low carbon： Choose energy-efficient appliances. In Hong Kong, air conditioner is the number one electricity-consuming household appliance. By keeping a reasonable temperature (e.g. 25℃) or use it alternately with fans, less heat and carbon will be released.

TRAVEL low carbon： If your destination is within walking distance, allow yourself enough time to go by foot. Otherwise, public transport in Hong Kong is plentiful and convenient, make good use of it! If you must drive, consider the followings to lower carbon emissions:
- Keep your tires fully inflated can help reduce carbon dioxide emission.
- Replace conventional vehicles with electric vehicles can help improve roadside air quality.
- Give your friends a ride. A full car is more efficient!

Further learning resources

Last Update:2025/10/21

Ways you can help: