4.2.2. Global Climate Indicators and Essential Climate Variable (ECV)

The World Meteorological Organization (WMO) State of the Global Climate uses seven Global Climate Indicators - Surface Temperature and Ocean Heat (Temperature and Energy); Atmospheric CO2 (Atmospheric composition); Ocean Acidification and Sea-level (Ocean and Water); Glaciers and Arctic and Antarctic Sea Ice Extent (Cryosphere) —to monitor the domains most relevant to climate change, 'without reducing climate change to only temperature'.

Global Climate Indicators are essential measures that help assess the impact of climate change. The WMO has highlighted seven key indicators that reflect various aspects of the climate system, rather than focusing solely on temperature. These indicators provide a broader view of climate change by including temperature, carbon dioxide levels, ocean acidity, sea level, and ice extent. Each of these indicators tells us something important about the climate and how it is changing over time.

Think of these indicators like the multiple dials on a car's dashboard. Just as each dial provides crucial information about the car’s performance (like speed, fuel level, and engine temperature), the Global Climate Indicators provide insights into different aspects of the Earth's climate system that can indicate overall health and stability.

In addition to the seven headline indicators, a supplementary set of subsidiary indicators is complimentarily available to offer information and contribute to a more comprehensive and detailed depiction of the evolving trends in their respective areas.

Along with the main seven indicators, there are additional subsidiary indicators that help further analyze climate changes. These supplementary indicators provide more detailed information that aids in understanding specific areas of concern and trends over time. By using both headline and subsidiary indicators, scientists can create a clearer picture of how climate change is affecting different systems.

Imagine you are trying to diagnose a health issue. The main symptoms (like a fever) might show that something is wrong, but lab tests and detailed medical evaluations (the subsidiary indicators) provide the specific insights needed for a more accurate diagnosis and treatment plan.

An Essential Climate Variable (ECV) is defined by WMO as 'a physical, chemical or biological variable or a group of linked variables that critically contributes to the characterization of Earth’s climate'.

Essential Climate Variables are key measurements needed to understand the climate system. These variables can be physical, chemical, or biological and relate to temperature, precipitation, atmospheric chemistry, and other important factors. By focusing on these ECVs, researchers can better grasp how climate conditions change and what that means for ecosystems and human activities.

Think of ECVs like the ingredients of a recipe. If you want to bake a cake (understand the climate), you need to know the essential ingredients like flour, sugar, and eggs. Similarly, ECVs represent the crucial data points needed to understand how climate systems operate.

These are compiled into datasets to provide empirical evidence that helps understand and predict the evolution of climate, and assess risks and enable attribution of climate events to underlying causes.

ECV datasets are databases that collect and organize information about the essential climate variables. These datasets allow scientists to analyze trends, make predictions about future climate changes, and understand the causes of climatic events. By assessing these factors, policymakers can make informed decisions on how to mitigate and adapt to climate change impacts.

Consider a weather forecast. Meteorologists use past data on temperature, humidity, and wind patterns (the ECV datasets) to predict future weather conditions. Just like how this data helps you prepare for the weather, ECV datasets help us prepare for future climate challenges and impacts.

EVC datasets further guide mitigation and adaptation measures, and supports the United Nations Framework Convention on Climate Change (UNFCCC) and Intergovernmental Panel on Climate Change (IPCC) efforts for assessment and creating climate services.

The information derived from ECV datasets is critical for international climate agreements and initiatives. They help guide actions aimed at both mitigating climate change (reducing its severity) and adapting to its impacts (adjusting to changes already occurring). The UNFCCC and IPCC rely on these datasets to assess the state of the climate and provide guidance to governments on effective climate policies.

Imagine a city council planning for emergency response after a hurricane. They would use accurate, detailed assessments of damage and weather patterns (similar to ECV datasets) to create effective response strategies. In the same way, the information from ECV datasets aids global bodies in developing strategies to combat climate change.

Assessments provide policymakers and the public with synthesized information on the state of the climate system, projected future changes, and associated impacts, by quantifying the observed changes and attributing them to human activities.

By synthesizing the information gained from ECV assessments, climate services can deliver actionable insights to various stakeholders, including governments, businesses, and communities. These assessments quantify changes in climate, helping to identify how human activities contribute to these changes and what future impacts might look like, thereby informing strategies for sustainability.

Think of these assessments like a doctor's diagnosis after examining a patient. The doctor tells you not only the current state of your health but also what to expect in the future and how certain lifestyle choices (akin to human activities) have contributed to your current health. This enables better planning and preventative measures.

The National Centers for Environmental Information (NCEI) of the U.S. National Oceanic and Atmospheric Administration (NOAA) and the U.S. GCOS Program at NCEI, maintains the Global Observing Systems Information Center (GOSIC) which provides further background, definitions, requirements, network information and data sources for ECVs.

The maintenance of databases and systems that monitor ECVs is crucial for ensuring the accuracy and reliability of climate data. Institutions like NOAA are responsible for compiling, managing, and making this data available to researchers, decision-makers, and the public. Their work ensures that the climate assessments are based on up-to-date and verifiable information.

You can liken this to a library that gathers and organizes books on a specific topic. Just like librarians work to ensure every book is cataloged correctly for easy access and verification, organizations like NCEI ensure that climate data is systematically organized and accurate for everyone to use.

These variables are monitored as per the GCOS Climate Monitoring Principles, which provide a standardized framework for monitoring and measuring key climate parameters consistently across different regions and over extended periods.

The GCOS Climate Monitoring Principles establish guidelines for how climate variables should be measured, ensuring consistency and reliability in the data collected worldwide. This standardized monitoring allows for better comparisons of climate data across different regions, contributing to a more comprehensive understanding of global climate trends.

Imagine a global sports tournament where all teams must follow the same rules and scoring methods. This consistency allows for fair competition and comparison of teams. Similarly, standardized monitoring principles ensure that climate data collection is uniform, making it possible to assess and compare climate change effects accurately.

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