Earth Could Spiral Into A ‘Hothouse’ State Even If We Reduce CO2 Emissions, Warns New Report

The world could be heading toward a “hothouse” state despite our current efforts to manage global warming, reveals a new paper published yesterday in the journal Proceedings of the National Academy of Sciences.

According to the article, Earth is in danger of plunging into an “irreversible pathway” of global warming triggered by its own natural cooling mechanisms, unless we do more to reduce carbon dioxide (CO2) emissions and keep the planet from warming 2 degrees Celsius (around 3.7 degrees Fahrenheit) above preindustrial levels.

That very goal is now being pursued through the Paris Climate Agreement, a global action plan signed in December 2015 by 179 countries worldwide and from which the United State withdrew last year, notes Live Science.

Through the Paris Agreement, these countries committed to a global effort of CO2 emission reduction that would keep the temperature rise we expect the see this century below the 2-degree mark, and ideally below 1.5 degrees Celsius over preindustrial levels. But a recent investigation concluded that this may not be enough to veer the planet away from a catastrophic path, the Inquisitr reported last month, and the new paper, an opinion article that draws on past research, refuels those concerns.

“This paper gives very strong scientific support […] that we should avoid coming too close or even reaching 2 degrees Celsius warming,” article co-author Johan Rockström, director of the Stockholm Resilience Center and a professor of water systems and global sustainability at Stockholm University in Sweden, said in a statement.

10 ‘Tipping Elements’ That Could Spell Disaster For Earth

Our planet relies on a series of mechanisms that help it maintain a balance amid the current trend of global warming. For instance, Earth’s oceans, trees, and soil soak up about half of the 40 billion tons of CO2 we release into the atmosphere every year through the burning of fossil fuels.

But these natural feedback mechanisms could soon turn against us, in a matter of a few decades, if the CO2 emissions continue on their current rate and the planet reaches a certain temperature threshold — which the article authors believe could be the 2-degree mark.

If this should happen, all the mechanisms that currently protect the planet from overheating would reverse, propelling Earth into a “hothouse” state. And all it takes is for just one of them to break down, warns the paper.

“When it crosses a tipping point, the feedback mechanism changes direction,” and starts putting CO2 back into the atmosphere, explained Rockström.

Together with his colleagues, the researchers identified 10 “tipping elements” that could go awry, dragging the others along with it in a catastrophic cascade effect.

The Huffington Post lists some of these “tipping elements,” which include the Amazon rainforest; the thawing of permafrost; the loss of coral reefs; the loss of Arctic summer sea ice and the reduction of Antarctic sea ice and polar ice sheets; the loss of methane hydrates from the ocean floor; and weaker land and ocean carbon sinks.

“These tipping elements can potentially act like a row of dominoes. Once one is pushed over, it pushes Earth towards another,” said Rockström.

Hothouse Earth

In case this happens, the planet might leave the interglacial cycle that it has being going through for the past 12,000 years — also known as the Holocene Epoch, whose latest chapter has recently been dubbed the Meghalayan Age, as reported by the Inquisitr — and plunge into a new age known as Hothouse Earth.

What would the planet look like then? Well, first of all, it would become uninhabitable in certain areas. That’s because the “hothouse” state comes with “boiling hot temperatures and towering seas,” notes the BBC.

In a Hothouse Earth, global temperatures would be 4 to 5 degrees Celsius (7 to 9 degrees Fahrenheit) higher than preindustrial levels and the planet would be plagued by extreme weather events, such as year-long droughts, frequent wildfires, and building-flattening hurricanes.

Sizzling temperatures near the equator and a 30- to 200-foot (10 to 60 meters) rise in sea levels would force the globe’s population to evacuate many of the planet’s region and amass near the poles.

“It may be very difficult or impossible to stop the whole row of dominoes from tumbling over. Places on Earth will become uninhabitable if ‘Hothouse Earth’ becomes the reality,” said Rockström.

What Can We Do TO Stop It?

According to Michael Mann, a professor of meteorology at Pennsylvania State University who wasn’t involved in the paper, the authors “make a credible case that we could, in the absence of aggressive near-term efforts to reduce carbon emissions, commit to truly dangerous and irreversible climate change in a matter of decades.”

To prevent that from happening, the entire world must come together and work toward reducing carbon emissions — not just on a national level, but on a planetary scale, reveals the paper.

“We are the ones in control right now, but once we go past 2 degrees, we see that the Earth system tips over from being a friend to a foe. We totally hand over our fate to an Earth system that starts rolling out of equilibrium,” said Rockström.

This can only be achieved by the efforts of a global community, point out Rockström and his colleagues, who advocate that the world’s counties help one other work toward this common goal.

This means “that it’s, scientifically speaking, completely unacceptable that a country like the U.S. leaves the Paris Agreement, because now more than ever, we need every country in the world to collectively decarbonize […] in order to secure a stable planet,” said Rockström.

One way to do this would be through investment funds created to help poorer nations reduce CO2 emissions, so that we stop burning fossil fuels by 2050.

In addition, we need to start working on technologies that suck CO2 from the atmosphere and store it underground, while also actively engaging in protecting forests, conserving biodiversity, and improving agricultural and soil management, reveals the paper.

Help could come from the tiniest change. For instance, the minuscule Azolla fern could become a worthy ally in our struggle to reduce the effects of climate change, per a recent Inquisitr report.
source: inquisitr.com

قال باحثون من أكثر من دولة إنه من غير المستبعد أن يستمر خطر تعرض العالم لدرجات حرارة مرتفعة بشكل غير معتاد، رغم اتفاقية باريس للمناخ التي تهدف لخفض الانبعاثات الاحتباسية التي تؤدي لارتفاع درجة حرارة الأرض.

وأوضح معهد بوتسدام الألماني لأبحاث المناخ، أن الباحثين توقعوا في مناقشة نشرت تفاصيلها اليوم، بمجلة بروسيدنجز الأمريكية، أن ترتفع درجات حرارة الأرض بواقع أربع إلى خمس درجات حرارة مئوية على المدى البعيد وأن يرتفع منسوب سطح البحر بواقع 10 إلى 60 مترا.

وركز الباحثون خلال النقاش بشكل خاص على ما يعرف بالعناصر المتحولة مثل الغطاء الثلجي لجزيرة جرينلاند أو الترب الصقيعية التي تتعرض للذوبان، وهما عاملان لهما تأثيرات متبادلة يمكن أن تزداد قوة.

وقال هانز يواخيم شيلنهوبر، أحد المشاركين في المناقشة، إنه من غير الواضح حتى الآن ما إذا كان من الممكن الإبقاء على النظام المناخي عند مستواه قبل العصر الصناعي من خلال “وقف” ارتفاع درجات حرارة الأرض عند درجتين مئويتين مقارنة بما كانت عليه في العصر قبل الصناعي.

وأوصى شيلنهوبر بأن يسارع البحث العلمي لدراسة هذا الخطر في أقرب وقت ممكن.

يذكر أن ألمانيا تتعرض حاليًا لموجة حر شديدة، حيث تصل درجات الحرارة في بعض المناطق أحيانا إلى 39 درجة مئوية، وحسب تقديرات خبراء المناخ، ولا تقتصر عواقب احترار الأرض على ارتفاع درجات الحرارة والجفاف فحسب، بل تشمل أيضًا موجات البرودة والعواصف الشديدة وهطول الأمطار بغزارة.

وكان علماء المناخ الأوروبيون قد أكدوا أن استفحال ظاهرة التغير المناخي لم تشمل منطقة حوض المتوسط فحسب، بل توسعت لتشمل منطقة البلطيق وشمال القارة المعروفة ببرودة طقسها، وامتدت إلى أقصى شرق القارة الآسيوية، والولايات المتحدة الأمريكية، داعين إلى ضرورة الإسراع بتنفيذ بنود اتفاقية باريس للمناخ الموقعة قبل ثلاث سنوات، نظرا لما تنطوي عليه من جهود لمكافحة تغير المناخ.