Energy
Energy systems depend on weather, water and climate. Rainfall, wind, sunshine and temperature all affect how energy is produced, transmitted and used. As extreme weather events increasingly affect energy systems, WMO helps Members and the sector use meteorological, hydrological and climate information to support resilient planning and operations.
Overview
The vulnerability of energy systems to weather, water and climate is a defining operational reality. Hydropower, the world’s largest source of renewable electricity, depends on rainfall, snowpack and glacier melt. Thermal power plants require large volumes of cooling water and lose efficiency or curtail output when rivers and lakes warm or run low. Wind and solar generation rise and fall with atmospheric conditions. Transmission and distribution networks are exposed to heatwaves, wildfires, storms, ice loading and flooding. Demand itself is weather-driven, with cooling and heating loads increasingly volatile.
Changing climate and weather patterns are amplifying every one of these exposures. Hotter, drier summers stress hydropower reservoirs and thermal plant cooling at exactly the moment cooling demand peaks. More intense storms, floods and wildfires damage assets designed for a more stable climate. Compound and cascading events, for example a heatwave combined with low wind output and reduced hydropower, can stress entire systems simultaneously. Historical design assumptions built on the idea that past climate conditions are a reliable guide to the future no longer hold.
For the energy sector, weather, water and climate have become operational variables that must be managed across every timescale, from real-time grid balancing to multi-decade investment planning.
Impact
The energy sector accounts for around 10% of global freshwater withdrawals, primarily for thermal plant cooling and hydropower operation. Hydropower remains the world’s largest source of renewable electricity, while a much larger share of global energy generation depends on water indirectly through cooling. The Intergovernmental Panel on Climate Change (IPCC) has assessed that both thermoelectric and hydropower sources are vulnerable to water stress in ways that can affect grid security and energy affordability.
Prolonged drought has cut hydropower output across southern Africa, Latin America, Europe and parts of Asia in recent years. The 2015–16 El Niño provides a clear example: rainfall in Colombia fell by around 40%, hydropower reservoir levels declined by 60–70%, and a system then reliant on hydropower for roughly three-quarters of its electricity was forced to rely on thermal power generation to maintain electricity supplies.
Warming rivers have forced curtailments of nuclear and thermal energy generation in several European countries and the United States while low water levels have constrained fuel and equipment transport on major inland waterways and shipping routes. Glacier retreat is also altering seasonal water availability for hydropower in the Andes, the Himalayas, the Alps and other mountain basins. Underlying these episodic disruptions is a longer-term trend: total terrestrial freshwater storage, which includes soil moisture, snow and ice, has declined globally at a rate of around one centimetre per year over the past two decades.
Heatwaves increase electricity demand for cooling while reducing the efficiency of thermal generation and the carrying capacity of transmission lines. Tropical cyclones, extratropical storms and floods can damage substations, transmission corridors, refineries and pipelines. Wildfires, which are becoming more frequent and intense in many fire-prone regions, can sever transmission lines, force precautionary shutoffs and reduce solar generation through smoke and ash. Cold extremes have triggered major outages where gas, coal and even nuclear assets were not prepared for sustained low temperatures, with cascading effects across electricity and heating systems.
Sea level rise compounds these exposures for the substantial share of global energy infrastructure sited on coastlines. Thermal and nuclear plants, refineries, liquefied natural gas (LNG) terminals, offshore platforms, ports and coastal substations face increasing risk from rising mean sea level, more frequent coastal flooding and intensified storm surges. Long-lived assets being designed and financed today must account for sea levels and storm surge risks that will continue to shift over their operating lifetimes.
WMO's response
WMO works with National Meteorological and Hydrological Services (NMHSs) and a broad network of partners, including the International Renewable Energy Agency (IRENA), the International Energy Agency (IEA), the International Atomic Energy Agency (IAEA) and the wider energy community, to help the sector manage weather, water and climate risks across timescales. Tailored services span nowcasting, sub-seasonal to seasonal forecasting, annual to decadal prediction and long-term climate projection, and underpin resource planning, operations and maintenance, risk management and investment decisions for renewables, thermal generation, nuclear power, grids and storage.
WMO supports hydropower planning and operation, cooling water management, and basin-level drought and flood early warning, drawing on the global hydrological observing and prediction infrastructure it coordinates.
Early warning systems for the energy sector, aligned with the global Early Warnings for All initiative, help anticipate disruption from extreme weather, drought and compound events.
Together with the United Nations Economic Commission for Europe (UNECE) and the United Nations Educational, Scientific and Cultural Organization (UNESCO), WMO co-coordinates the United Nations Water Expert Group on Water and Climate Change, contributing to United Nations-system efforts to align water and energy decision-making in the climate context. Joint analytical work with IRENA helps translate climate science into practical information for energy planners, operators, regulators and investors.
WMO also supports capacity development for NMHSs to deliver decision-ready information to the energy sector, through training, regional projects and demonstration services. It also coordinates the international data exchange and standards on which energy operators worldwide depend.
By combining atmospheric, hydrological and climate expertise, WMO makes a unique contribution to the global energy conversation, one that the sector increasingly requires as weather and climate variability reshape the conditions under which energy systems operate.
