August - September 2021
Climate change kicks into gear
New Zealand has warmed up by 1.1 degrees and annual temperature changes have emerged above natural variability over the country in the last 110 years, according to the Intergovernmental Panel on Climate Change report east of both islands, with less rainfall in the west and central North Island. Glaciers have retreated and are projected to retreat further. Rain will increase in southern New Zealand. A general increase in annual maximum precipitation even in some areas of decreased annual precipitation. Some projected changes show important seasonal differences. Meanwhile, Borge Brende, president of the World Economic Forum, says the new report shows the recent global forest fires and floods of recent weeks delivered a clear message: the world needs to stop putting carbon in the atmosphere. “Extreme heat is not a future problem. It is already here. 2010 to 2019 was the hottest decade ever recorded, and temperatures will continue to rise unless dramatic action is taken. Industry is responsible for nearly a third of global emissions.” The evidence is “indisputable” that human activity is causing climate change, that it is happening to a greater extent and at a faster pace than earlier research findings indicated. Humanity must reduce emissions of greenhouse gasses by a lot and must prepare for the impact of climate change caused by past, present and future emissions.
ENVIRONMENT
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cientists are observing changes in the Earth’s climate in every part of the world region across the whole climate system, the report states. Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years. Some of the changes already set in motion, such as continued sea level rise, are irreversible over hundreds to thousands of years. In New Zealand, heat extremes have increased, cold extremes have decreased, and these trends are projected to continue, the report says. “Relative sea level rose at a rate higher than the global average in recent decades; sandy shorelines have retreated in many locations.” Relative sea level rise is projected to continue in the 21st century and beyond, contributing to increased coastal flooding and shoreline retreat along sandy coasts throughout Australasia. Snow cover and depth have decreased and are projected to decrease further. Frequency of extreme fire weather days has increased, and the fire season has become longer since 1950 at many locations, the report says. The intensity, frequency and duration of fire weather events are projected to most likely increase throughout Australasia. Heavy rainfall and river floods are projected to increase as will marine heatwaves. The report says it expects projected increase in winter and spring rainfall in the west and south of New Zealand, with less rainfall in the east and north, and more summer rainfall in the
The far-reaching report is the first released from the IPCC in eight years. The temperatures are rising from a higher level and faster than the previous report. The oceans are becoming more acidic faster than previously estimated. Tolerance for denial and scepticism will likely decline as predicted extreme weather events affect all parts of our planet with growing severity and frequency. New Zealand’s Climate Change Commission’s advice on budgets and ways to reduce emissions is entirely consistent with the evidence and the need for action that is sustained over years to come. Meanwhile, the world strong and sustained reductions in emissions of carbon dioxide (CO2) and other greenhouse gases would limit climate change.
While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilise, according to the IPCC Working Group I report, Climate Change 2021: the Physical Science Basis. The report provides new estimates of the chances of crossing the global warming level of 1.5°C in the next decades, and finds that unless there are immediate, rapid and large scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach. Emissions of greenhouse gases from human activities are responsible for approximately 1.1°C of warming since 1850-1900 and finds that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming. www.makelemonade.nz infrastructurenews.co.nz 37
