Understanding the climate crisis can be quite difficult at times. This article is here to help.

The terms “climate change” and “global warming” are commonly used interchangeably but have distinct meanings. As do the terms "weather" and "climate", though they refer to events with broadly different timescales and spatial areas.

Climate vs Weather

Climate refers to the long-term regional or even global average of temperature, humidity and rainfall patterns over years or decades.

Weather, on the other hand, refers to atmospheric conditions that occur locally over short periods of time, from minutes to hours or days. Such as rain, snow, clouds or storms.

What is Global Warming?

Global warming is the long-term heating of Earth’s climate system observed since the pre-industrial period due to human activities, which increase levels of heat-trapping greenhouse gases in Earth’s atmosphere. Most commonly measured as the average increase in Earth’s global surface temperature, the term is commonly used interchangeably with the term climate change, though the latter refers to both human and naturally produced warming.

Since the pre-industrial period, human activities are estimated to have increased Earth’s global average temperature by about 1 degree Celsius, a number that is rising by 0.2 degrees Celsius per decade. Most of the current warming trend is extremely likely to be the result of human activity since the 1950s and is proceeding at an unprecedented rate.

What is Climate Change?

Climate change is a long-term change in the average weather patterns that have come to define Earth’s local, regional and global climates.

Changes observed in Earth’s climate since the 20th century are primarily caused by human activities, particularly fossil fuel burning, raising Earth’s average surface temperature. Natural processes can also contribute to climate change, including external forcings (e.g., volcanic activity, changes in the Sun’s energy output, variations in Earth’s orbit due to Milankovitch cycles) and internal variability (e.g., cyclical ocean patterns).

Scientists use observations from the air, ground and space, along with theoretical models, to monitor and study past, present and future climate change. Climate data records provide evidence of key indicators, such as global land and ocean temperature increases; rising sea levels; ice loss at Earth’s poles and in mountain glaciers; frequency and severity changes in extreme weather such as droughts, heatwaves, hurricanes, wildfires, floods and precipitation; and cloud and vegetation cover changes. It isn't a hoax.

Impacts

Due to the actions of our species, the amount of CO2 in the atmosphere is now over 400 ppm. This is causing a variety of changes to the climate. The frequency / intensity of extreme events like wildfires and storms are increasing. Rainfall patterns are changing across the globe with increasing floods and droughts. Glaciers all over the world are retreating. Additionally there are also changes between seasons in different regions. Growing seasons have lengthened with spring starting earlier and autumn/winter later. Sea-levels have risen about 17 cm since 1900 because of thermal expansion of ocean water and melting glacier ice. Sea Level Rise has increased from ~1mm/year 100 years ago to 3 mm/year today. Already many species are changing their behaviour and where they live in a fight for survival against increasingly harsh conditions. These effects will only get worse as human induced climate change progresses. The only likely way out, is to be worried, to try to salvage the situation while we can.

What can you do?

Vote. Vote for whomever you believe will do the best at caring for this nation and its environment. Climate change is a real issue, despite the fact that we don’t notice it. You only need to look at the rise in cyclonic activity and unusual seasonal variation in temperature to see this clearly. Voting for political parties or individuals who you believe will aid in New Zealand’s efforts to stop climate change is the first and best step towards helping our global climate.