{"id":2856,"date":"2021-07-13T03:39:57","date_gmt":"2021-07-13T03:39:57","guid":{"rendered":"http:\/\/eos.co.id\/main\/?p=2856"},"modified":"2021-07-13T03:41:52","modified_gmt":"2021-07-13T03:41:52","slug":"demystifying-ocean-based-carbon-dioxide-removal-an-explainer","status":"publish","type":"post","link":"https:\/\/eos.co.id\/main\/uncategorized\/demystifying-ocean-based-carbon-dioxide-removal-an-explainer\/","title":{"rendered":"Demystifying Ocean-based Carbon Dioxide Removal: An Explainer"},"content":{"rendered":"\n

Source >>><\/a><\/h3>\n\n\n\n

Twitter share link<\/em>\u00a0<\/a>Linkedin share link<\/em>\u00a0<\/a>Facebook share link<\/em>\u00a0<\/a>Print<\/em><\/p>\n\n\n\n

Email share link<\/em><\/a><\/p>\n\n\n\n

January 18, 2021 By Antonius Gagern, CEA Consulting<\/p>\n\n\n\n

Climate change has become the biggest and fastest-growing threat to the ocean, due to temperature increases, acidification, sea-level rise, and hypoxic conditions. Mitigation efforts alone will be insufficient to stabilize the climate, as we must remove 100\u20131000 billion tons of carbon dioxide (CO2<\/sub>) from the atmosphere before the end of the century to reach long-term climate goals.1<\/sup>\u00a0This is an enormous challenge, calling for an \u201call cards on the table\u201d approach to identifying scalable, affordable, and safe carbon dioxide removal (CDR) mechanisms. The ocean\u2019s natural carbon pumps play a significant role in controlling the climate and will, ultimately, absorb much of the excess heat and CO2<\/sub>\u00a0in the atmosphere, but not in our lifetime or the lifetime of our children and grandchildren.<\/p>\n\n\n\n

Ocean-based CDR mechanisms<\/a> are currently being explored as part of a growing portfolio of CDR approaches. Philanthropy can play an important role in shaping the maturation process of ocean-based CDR approaches by ensuring transparent, inclusive, and responsible research and policy frameworks.<\/p>\n\n\n\n

Philanthropy can play an important role in shaping the maturation process of ocean-based CDR approaches by ensuring transparent, inclusive, and responsible research and policy frameworks.<\/p><\/blockquote>\n\n\n\n

Removing carbon from the atmosphere is necessary to stabilize the climate and guarantee the durability of conservation efforts.<\/h2>\n\n\n\n

Today, we are on track to increase average global temperatures by 3-4 degrees Celsius compared to pre-industrial levels within the next 80 years alone.<\/strong>2<\/sup>\u00a0Since the 1850s, we have emitted 1.6 trillion tons of planet-warming carbon dioxide CO2<\/sub>\u00a0into the atmosphere. Based on our global\u00a0\u201cemissions gap,\u201d<\/a>\u00a0the world is projected to reach a catastrophic temperature rise this century (in the absence of rapid decarbonization). The Industrial Revolution fueled a global economy and lifestyle that many in the industrialized world have come to rely on: heated and cooled homes, stocked fridges, global trade, and cheap, on-demand personal transportation. The resulting rapidly increasing atmospheric CO2<\/sub>\u00a0concentrations are making the planet warmer and the ocean more acidic, disrupting the global climate system. Concerns about the physical impacts of climate change have grown stronger and louder as\u00a0heatwaves, wildfires, storms, floods, and falling agricultural yields<\/a>\u00a0are affecting more and more people. However, the international response to these threats has largely been slow and insufficient, both in terms of verifiable private sector commitments and nationally binding targets for emission reductions. The reasons leaders are finding climate change so difficult to grapple with are political, economic, ideological, and even psychological in nature.<\/p>\n\n\n\n

A 1.5-degree Celsius future has become impossible to achieve without drawing CO2<\/sub> out of the atmosphere and storing it safely and permanently.<\/strong> To limit warming to 1.5 degrees C by 21003<\/sup> with a 66 percent probability, we must not emit more than 230 Gt of CO2<\/sub> between 2020 and 2100. At current rates of emissions, this \u201ccarbon budget\u201d will be spent in less than five years. Even the most aggressive projections of emission reductions do not get anywhere close to staying within the 1.5-degree carbon budget. The Intergovernmental Panel on Climate Change (IPCC) suggests that even aggressive mitigation scenarios, that is, preventing the release of CO2<\/sub> into the atmosphere\u2014will have to be complemented with carbon dioxide removal (CDR) on the order of 100\u20131000 billion tons before the end of the 21st century.4<\/sup> Removal is literally bringing back down to Earth the CO2<\/sub> that has accumulated since the Industrial Revolution. This legacy \u201cCO2<\/sub>\u201d will cause the planet to warm, even once mitigatio\u2014solar, wind, electric vehicles\u2014takes new emissions to zero.\"Figure<\/p>\n\n\n\n

Figure 1. Impact of climate change on atmospheric temperature (average above pre-industrial), sea-level rise and pH. Source: en-roads.climateinteractive.org, using baseline projections<\/p>\n\n\n\n

Marine conservation priorities and past victories may be swamped by climate change.<\/strong>\u00a0Biodiversity in the ocean has evolved in the absence of human-induced stressors such as overfishing, pollution, shipping, habitat destruction and fragmentation, and invasion of new species. Even without the impacts of climate change and ocean acidification, this\u00a0\u2018cumulative human impact\u2019<\/a>\u00a0on the ocean has considerably diminished marine biodiversity. The effects of climate change have now become the biggest and fastest-growing contributors to cumulative human impact on the ocean.5<\/sup>\u00a0A recent report from the\u00a0Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)<\/a>\u00a0found that approximately one million plant and animal species are threatened by extinction, many within decades and that human activities have significantly altered two-thirds of the ocean.6<\/sup>\u00a0As a result, many prominent efforts to safeguard biodiversity, sustainably manage fisheries, and alleviate poverty in coastal communities around the world are at risk due to climate change: we can work locally and nationally to reduce the detrimental effects of pollution, overfishing, or habitat destruction, but ocean acidification, rising temperatures, sea-level rise, and hypoxia are largely outside of our control. A thoughtfully examined and determined global effort to remove hundreds of billions of atmospheric CO2<\/sub>\u00a0is an important part of the solution set currently overlooked.<\/p>\n\n\n\n

The effects of climate change have now become the biggest and fastest-growing contributors to cumulative human impact on the ocean.<\/p><\/blockquote>\n\n\n\n

The potential and risks of ocean-based CDR must be explored in detail and with care.<\/h2>\n\n\n\n

The ocean might be a powerful ally to large-scale CDR. As there is no single silver bullet CDR method, a portfolio approach to negative emission technologies must be pursued.<\/strong>\u00a0Removing hundreds of billions of tons of CO2<\/sub>\u00a0from the atmosphere is an enormous challenge. Some of the most discussed CDR approaches in the terrestrial realm include direct air capture, bioenergy with carbon capture and storage, reforestation, and agricultural practices that increase the burial rate of organic carbon. While these approaches hold significant promise, there are important impediments to their quick scale-up, including cost, energy requirements, and land-use implications. Additionally, some climate-caused\u00a0\u201cfeedbacks\u201d<\/a>\u00a0such as drought, fire, and pests already are impairing the ability of land-based solutions such as trees to remove as much CO2<\/sub>\u00a0as once hoped. Direct air capture is considered to be one of the most promising proposals today as the technology has been successfully piloted and seems highly scalable. Nonetheless, the costs of net carbon removal remain prohibitively expensive and the technology is water and energy-intensive. It is widely acknowledged that we will need a portfolio approach to CDR, given the urgency and scale of the challenge.7<\/sup><\/p>\n\n\n\n

It is widely acknowledged that we will need a portfolio approach to CDR, given the urgency and scale of the challenge.<\/p><\/blockquote>\n\n\n\n

The ocean plays an important role in the global carbon cycle and has contributed to the stabilization of the global climate for millions of years.<\/strong> Primary producers such as phytoplankton, mangroves, and seaweed turn CO2<\/sub> into organic carbon, some of which escapes the food web and is permanently sequestered in coastal soils and the seabed. Over geologic timescales, the weathering of rock washes alkaline molecules into the ocean and converts dissolved CO2<\/sub> into carbonates and bicarbonates, thereby storing carbon for tens to hundreds of thousands of years in seawater. Overall, the ocean today stores 38 trillion tons of carbon (equivalent to 140 trillion tons of CO2<\/sub>), approximately 50 times more than is contained in the atmosphere.\"Figure<\/p>\n\n\n\n

Figure 2. CO2<\/sub> sources, sinks, and flows. Source: www.globalcarbonproject.org<\/p>\n\n\n\n

Several ocean-based approaches have emerged as potentially scalable contributions to a growing CDR portfolio.<\/strong> These approaches aim to boost the biotic and abiotic carbon pumps that naturally remove sequester CO2, thereby \u201cpulling\u201d more CO2<\/sub> from the atmosphere into the ocean without increasing ocean acidification. (A detailed overview of approaches can be found at www.oceancdr.net<\/a>.)<\/p>\n\n\n\n