Our climate is changing. During the period 2011 – 2020, global surface temperature was about 1.1 degrees Celsius above the 1850 – 1900 level. The summer of 2023 was the hottest of its kind on record at 2.1 degrees Celsius warmer relative to the average summer for the period 1951 – 1980. In 2024, the average global mean near surface temperature was 1.55 degrees Celsius which is ± 0.13 degrees Celsius above the 1850 – 1900 average making 2024 the warmest year in record in the past 175 years. Human activity, mainly through emissions of greenhouse gases is the main cause of global warming. The main greenhouse gases responsible for global warming, hence climate change include water vapor (H20) carbon dioxide (C02), ammonium (CH4), nitrous oxide (N20) and halogen containing gases. C02 is the dominant greenhouse gas with human activity emitting additional amounts than any other greenhouse gas. In 2023, the global annual average mole fraction of C02 concentration in the atmosphere reached a new observed high at 240.0 ± 0.1 parts per million (ppm), which was 2.3 ppm higher than 2022 level and 151% of the pre-industrial concentration in 1750. CH4, N20 and halogen containing gases have significant global warming effect in relation to their atmospheric concentration due to their two main characteristics namely radiative efficiency and atmospheric residence time. Over the past one and half centuries, industrial activities and land use changes have played a key role in increasing the total amount of greenhouse gases in the atmosphere except for H20 leading to an average increase of global temperature of more than 1 degree Celsius since the preindustrial age.
 

Major causes of climate change

1. Power generation from burning fossil fuels, coal, oil and gas.

2. Manufacturing industries through burning fossil fuels, coal, oil and gas, as well as use of chemicals.

3. Deforestation thus releasing the carbon stored in trees.

4. Transportation from trucks, cars, ships and planes that run on fossil fuels.

5. Farming mainly from deforestation and clearance of vegetation for farming and grazing, digestion by cows and sheep, production and use of manure and fertilizer, and use of fossil fuels in equipment.

6. Powering buildings from coal, oil and natural gas.

7. Overconsumption leading to over extraction of natural resources.

 

Effects of climate change

1. Hotter temperatures due to the Earth surface absorbing more energy than it radiates back to space.

2. Changes in precipitation patterns and more severe storms due to increased evaporation.

3. Increased droughts and wildfires due to increased evaporation and lack of precipitation

4. Warming, and rising ocean due to ice melting from glaciers and the Antarctic ice sheet

5. Biodiversity loss as animal and plants species struggle to cope with changes (temperature, pollution of water, soil and air), habitat fragmentation and loss, over-exploitation, spread of invasive species, and land use change.

6. Increased vulnerability particularly for low income socially marginalized populations in urban settings with poor infrastructure

7. Soil degradation due to soil erosion, flooding, reduction in organic matter, loss of soil biodiversity, landslides and desertification

8. Increased health risks to humans, animals and plants.

9. Poverty and displacement due to loss of livelihoods and conflicts brought about by multiple and intersecting crises.

10. More intense wildfires due to increased drying of organic matter in forests.

 

Efforts to mitigate climate change and adapt to its effect are important and urgent. These should amongst others target land and oceans which have in the past six decades played a crucial role as carbon sinks with near sustained proportions. The scale of the challenge involved requires global effort with collaboration at individual, societal, organizational and governmental level. We seek to stimulate momentum to sustainability through careful analysis of the problems and co-creation of mutually reinforcing solutions that deliver results at scale with a special focus on the food system.