NASA, United Nations & WMO: What is Climate Change?

Climate change refers to long-term shifts in global temperatures and weather patterns according to the United Nations (UN). 

While these shifts can occur naturally through changes in the sun’s activity, volcanic eruptions or ocean cycles, scientists agree that since the 1800s the main driver has been human activity, the UN says.

The UN states that: “Burning fossil fuels releases GHGs like carbon dioxide and methane which then trap heat in the Earth’s atmosphere, acting like a blanket and causing temperatures to rise.” 

Other contributors include deforestation, agriculture and industrial operations. 

“Trees are known for their capacity to absorb carbon dioxide through photosynthesis,” says Earth.org. 

“Healthy forests act as extremely valuable carbon sinks, absorbing an estimated 16 billion tonnes of CO₂ per year and currently holding 861 gigatonnes of carbon in their branches, leaves, roots and soils.

“Deforestation is turning these sinks into huge net emitters, threatening global climate action and contributing to a steep rise in global temperatures.”

Together, energy, industry, transport, agriculture and land use account for the bulk of global emissions.

How climate change is measured

Organisations such as NASA and the World Meteorological Organization (WMO) track climate change using ground, air and satellite data. 

According to NASA, indicators include:

• Rising land and ocean temperatures
  
  
• Melting glaciers and polar ice sheets
  
  
• Rising sea levels
  
  
• Increasing frequency and intensity of extreme weather events such as hurricanes, heatwaves, floods, wildfires, droughts and precipitation.

Climate change and global warming are sometimes used interchangeably, but there is a distinction.

NASA explains that “global warming” refers specifically to the rise in Earth’s average surface temperature, while “climate change” encompasses a wider range of shifts, including rainfall, storm patterns and ocean currents.

The global frameworks for action

The world has recognised the urgency of the crisis through international agreements:

• The Paris Agreement (2015): Signed by almost every country, it set the goal of limiting global temperature rise to well below 2°C, ideally 1.5°C, compared to pre-industrial levels.
  
  
• The Sustainable Development Goals (SDGs): Adopted by the UN, Goal 13 specifically addresses urgent action to combat climate change and its impacts.
  
  
• The UN Framework Convention on Climate Change (UNFCCC): Provides the overall structure for global cooperation on climate issues.

According to the IPCC (Intergovernmental Panel on Climate Change​​​​​​​), emissions must be cut by half by 2030 and reach net zero by 2050 to avoid catastrophic consequences. 

“Having the right policies, infrastructure and technology in place to enable changes to our lifestyles and behaviour can result in a 40-70% reduction in greenhouse gas emissions by 2050,” says Priyadarshi Shukla, IPCC Working Group III Co-Chair.

“This offers significant untapped potential. 

“The evidence also shows that these lifestyle changes can improve our health and wellbeing.”

Key organisations tackling climate change

United Nations

The UN plays a central role through the UNFCCC, IPCC reports and coordination of global climate summits (COP meetings). 

The UN Environment Programme (UNEP) stands at the core of the action in the fight against climate change. 

UNEP states “We tackle the climate crisis on a variety of fronts:

• Encouraging the transition to low- and zero-carbon emissions in key sectors such as energy, agriculture, buildings, forestry, industry and transport
• Working with governments, civil society and the private sector to improve air quality and reduce emissions of short-lived climate pollutants
• Protecting and restoring natural ecosystems such as forests, coral reefs and peatlands while combating the sources of degradation
• Empowering communities to adapt to changing conditions by building resilient ecological foundations
• Supporting public engagement and behaviour change through global campaigns and education programmes.”

It provides science, frameworks and diplomacy to align global action.

NASA

Beyond monitoring climate indicators, NASA develops models to predict future climate scenarios. 

NASA aids the fight against climate change by collecting vast amounts of Earth-observing data from its satellites and the International Space Station (ISS) to monitor climate processes, track long-term trends like sea level rise and inform global climate models.

Intergovernmental Panel on Climate Change (IPCC)

The IPCC produces scientific assessment reports that guide governments on mitigation and adaptation strategies. 

Its 2018 report was critical in highlighting the benefits of limiting warming to 1.5°C rather than 2°C.

The Met Office (UK)

The Met Office provides climate science, modelling and weather projections that help governments and businesses prepare for future risks.

Non-Governmental Organisations (NGOs)

• WaterAid: Focuses on building resilience in communities facing water scarcity due to suspected climate stress.
  
  
• WWF: Protects biodiversity and ecosystems, advocating for stronger climate policies.
  
  
• Greenpeace: Campaigns for fossil fuel phase-out and expansion of renewable energy.

Private sector leaders

Many businesses are embedding climate goals into their strategies:

• Microsoft and Google have committed to achieving carbon negativity.
  
  
• Ørsted transitioned from fossil fuels to become a leader in offshore wind energy.
  
  
• Tesla drives decarbonisation of the transport sector through EVs and energy storage solutions.