Daily Bulletin


News

  • Written by Laura Revell, Senior Lecturer in Environmental Physics, University of Canterbury
Climate Explained: what Earth would be like if we hadn't pumped greenhouse gases into the atmosphere CC BY-ND Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change. If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz This week, Climate Explained answers two similar questions. If humans had not contributed to greenhouses gases in any way at all, what would the global temperature be today, compared to the 1800s before industrialisation? and My question is what happens when all the greenhouse gases are eliminated? What keeps the planet from cooling past a point that is good? Earth’s atmosphere is a remarkably thin layer of gases that sustain life. The diameter of Earth is 12,742km and the atmosphere is about 100km thick. If you took a model globe and wrapped it up, a single sheet of tissue paper would represent the thickness of the atmosphere. The gases that make up Earth’s atmosphere are mostly nitrogen and oxygen, and small quantities of trace gases such as argon, neon, helium, the protective ozone layer and various greenhouse gases – so named because they trap heat emitted by Earth. The most abundant greenhouse gas in Earth’s atmosphere is water vapour - and it is this gas that provides the natural greenhouse effect. Without this and the naturally occurring quantities of other greenhouse gases, Earth would be about 33℃ colder and uninhabitable to life as we know it. Changing Earth’s atmosphere Since pre-industrial times, human activities have led to the accumulation of greenhouse gases such as carbon dioxide, methane and nitrous oxide in the atmosphere. The concentration of atmospheric carbon dioxide has risen from about 280 parts per million (ppm) before the first industrial revolution some 250 years ago, to a new high since records began of just over 417ppm. As a result of continued increases, the global average temperature has climbed by just over 1℃ since pre-industrial times. Read more: Climate explained: why carbon dioxide has such outsized influence on Earth's climate While these long-lived greenhouse gases have raised Earth’s average surface temperature, human activities have altered atmospheric composition in other ways as well. Particulate matter in the atmosphere, such as soot and dust, can cause health problems and degrades air quality in many industrialised and urban regions. Particulate matter can partially offset greenhouse gas warming, but its climate effects depend on its composition and geographical distribution. Climate in the southern hemisphere has also been affected by chlorofluorocarbons (CFCs), which led to the development of the Antarctic ozone hole. If people had not altered the composition of the atmosphere at all through emitting greenhouse gases, particulate matter and ozone-destroying CFCs, we would expect the global average temperature today to be similar to the pre-industrial period – although some short-term variation associated with the Sun, volcanic eruptions and internal variability would still have occurred. Read more: What is a pre-industrial climate and why does it matter? In a world that is about 1℃ warmer than during pre-industrial times, New Zealand is already facing the environmental and economic costs associated with climate change. The former head of the UN Framework Convention on Climate Change (UNFCCC), Christiana Figueres, argues that with trillions of dollars being spent around the world in economic stimulus packages following the COVID-19 pandemic, we need strong commitments to a low-carbon future if the world is to limit warming to 1.5℃ above pre-industrial levels. What needs to happen Greenhouse gases have long lifetimes – about a decade for methane and hundreds to thousands of years for carbon dioxide. We will need to reduce emissions aggressively over a sustained period, until their abundance in the atmosphere starts to decline. When New Zealand entered the Level 4 coronavirus lockdown in March 2020, almost two weeks passed (the incubation period of the virus) before the number of new cases started to decline. Waiting for atmospheric carbon dioxide concentrations to decrease, even while we reduce emissions, will be similar, except we’ll be waiting for decades. It is very unlikely that we could ever reduce greenhouse gas concentrations to the point that it becomes dangerous for life as we know it. Doing so would involve overcoming the natural greenhouse effect. Recent research into greenhouse gas emission scenarios provides guidance on what will need to happen to stabilise Earth’s temperature at 1.5℃ above pre-industrial levels. A rapid transition away from fossil fuels toward low-carbon energy is imperative; some form of carbon dioxide capture to remove it from the atmosphere may also be necessary. Short-term and scattered climate policy will not be sufficient to support the transitions we need, and achieving 1.5℃ will not be possible as long as global inequalities remain high.

Authors: Laura Revell, Senior Lecturer in Environmental Physics, University of Canterbury

Read more https://theconversation.com/climate-explained-what-earth-would-be-like-if-we-hadnt-pumped-greenhouse-gases-into-the-atmosphere-141194

Writers Wanted

Behind Victoria's decision to open primary schools to all students: report shows COVID transmission is rare

arrow_forward

As universities face losing 1 in 10 staff, COVID-driven cuts create 4 key risks

arrow_forward

Birthdays, holidays, Christmas without mum or dad: how to support kids with a parent away fighting fires

arrow_forward

The Conversation
INTERWEBS DIGITAL AGENCY

Politics

Did BLM Really Change the US Police Work?

The Black Lives Matter (BLM) movement has proven that the power of the state rests in the hands of the people it governs. Following the death of 46-year-old black American George Floyd in a case of ...

a Guest Writer - avatar a Guest Writer

Scott Morrison: the right man at the right time

Australia is not at war with another nation or ideology in August 2020 but the nation is in conflict. There are serious threats from China and there are many challenges flowing from the pandemic tha...

Greg Rogers - avatar Greg Rogers

Prime Minister National Cabinet Statement

The National Cabinet met today to discuss Australia’s COVID-19 response, the Victoria outbreak, easing restrictions, helping Australians prepare to go back to work in a COVID-safe environment an...

Scott Morrison - avatar Scott Morrison

Business News

What Are The Qualities Of A Good Rubbish Removal Company?

It’s common for residential and commercial properties to have wastes. Families will usually have food wastes, while businesses will have to dispose of toxic wastes regularly. Different wastes ar...

News Company - avatar News Company

5 Ways a Printed Marquee Can Help You Sell More at Markets

If you’re a local business owner, you probably already know that outdoor markets are a great way to reach customers and sell your product. If you already have permanent premises, they allow you ...

News Company - avatar News Company

5 Essential Tools for Working Remotely in 2020

The average, modern office worker spends 8 hours a day, 5 days a week in a company building. Since the start of COVID, however, many of these companies have allowed workers to work from home due...

News Company - avatar News Company



News Company Media Core

Content & Technology Connecting Global Audiences

More Information - Less Opinion