Climate Change

Measuring Climate Change

There is no single instrument measuring climate change. Instead there are thousands of measuring devices spread across the globe, on land, under the sea and in the air. Countless empirical tests of numerous different hypotheses have now built up a massive body of Earth science knowledge. This repeated testing has refined the understanding of many aspects of the climate system, from deep oceanic circulation to stratospheric chemistry.

Climate science in recent decades has seen an increasing rate of advancement, particularly in field research and notably through the evolution of measuring climate change methodology and tools, including the models and observations that support and enable the research. During the last four decades, the rate at which scientists have added to the body of knowledge of atmospheric and oceanic processes has accelerated dramatically.

There are a number of key factors in measuring climate change, and they are broadly categorized below.

Temperature When measuring climate change this is a primary and can be measured or reconstructed for the Earth's surface, and sea surface temperature (SST).

Precipitation (rainfall, snowfall etc) offers another indicator of relative climate variation and may include humidity or water balance, and water quality.

Biomass and vegetation patterns may be discerned in a variety of ways and provide evidence of how ecosystems change to adapt to climate change.

Sea Level measurements reflect changes in shoreline and usually relate to the degree of ice coverage in high latitudes and elevations.

Solar Activity can influence climate, primarily through changes in the intensity of solar radiation.

Volcanic Eruptions, like solar radiation, can alter climate due to the aerosols that are emitted into the atmosphere and alter climate patterns.

Chemical composition of air or water can be measured by tracking levels of greenhouse gases such as carbon dioxide and methane, and measuring ratios of oxygen isotopes. Research indicates a strong correlation between the percent of carbon dioxide in the atmosphere and the Earth's mean temperature.

The history of the effort to document and understand climate change is often complex, marked by successes and failures, and has followed a very uneven pace. Testing scientific findings and openly discussing the test results has been the key to the remarkable progress that's been made. Much published research and many notable scientific advances have occurred in the last few decades, including advances in the understanding and treatment of uncertainty. Fortunately, science is inherently self-correcting; incorrect or incomplete scientific concepts ultimately do not survive repeated testing against observations of nature.