Anthropogenic emissions of short-lived gases and their environmental impacts

全球气候直接影响我们生活的许多方面，如粮食安全、水资源和健康，从而使气候变化成为我们这个时代的重大挑战之一。气候是由人类活动释放的化学气体改变的，但也可能来自海洋、陆地和生物圈。我们只能通过研究整个地球系统来推进我们对全球气候变化的理解，因为这两者通过复杂的物理、化学和生物相互作用而联系在一起。我的研究目标是通过将大气与海洋、极地和陆地环境联系起来，了解和预测人类活动如何影响大气化学和气候。首先，我将调查源于海洋中生物活动的气体，即所谓的海洋生物成因痕量气体。包括溴在内的由大型藻类产生的海洋气体可能会导致地球高层大气中臭氧层的耗尽。大规模大型藻类养殖场目前被认为是消除大气中二氧化碳和抑制气候变化的一种选择。然而，这样的农场可能导致溴化气体产量的急剧增加，并威胁到臭氧的恢复。这项工作将展示大型藻类如何影响大气化学、空气质量，最重要的是，影响全球臭氧恢复。特别是，我将调查高纬度的大型藻类养殖场，如加拿大大陆架地带，是否比热带的养殖场对臭氧层的危害更小。第二，我的研究将集中在未来的航运活动及其对北极环境的影响。目前的气候变化导致海冰急剧融化，为经济上可行的货物和旅游航运打开了北极的大门。不断增加的交通流量将给北极地区带来更大的废气和颗粒物排放，加剧空气污染，影响气候。此外，这些排放将通过增加海洋环境的营养物质来影响北冰洋，从而影响海洋生产和生态系统。这项工作将调查未来北极航运排放对空气质量和海洋营养物质供应的影响。特别是，这项研究将侧重于通过加拿大北极群岛及其沿线的航运路线及其对环境的影响。第三，我将调查工业、农业和野火排放到大气中的人为污染物。我将重点讨论在大气中停留不到1-2个月的气体，即所谓的短期气候作用力。这些气体既可以使环境变暖，也可以使环境变冷，这取决于物种本身，也取决于它们排放的时间、数量和地点。这项工作将量化短期气候作用力的排放量，特别是来自中高纬度北部国家的排放量。由于这些气体对北极环境起着很大的作用，排放估计将提供有关它们对气候影响的重要信息。

Global climate directly affects many aspects of our lives such as food security, water resources, and health, thus making climate change one the big challenges of our time. Climate is altered by chemical gases that are released from human activities, but can also originate from the ocean, land and biosphere. We can only advance our understanding of global climate change by investigating the entire Earth system, as the two are connected by complex physical, chemical and biological interactions. The goals of my research are to understand and predict how anthropogenic activities impact atmospheric chemistry and climate by linking the atmosphere with the marine, polar and terrestrial environment. First, I will investigate gases that stem from biological activities in the ocean, so-called marine biogenic trace gases. Marine gases that include bromine and are produced by macroalgae, can contribute to the depletion of the Earth's ozone layer in the upper atmosphere. Large-scale macroalgae farms are currently discussed as an option to remove carbon dioxide from the atmosphere and dampen climate change. However, such farms could lead to a steep increase in the production of brominated gases and threaten ozone recovery. This work will show how macroalgae can impact atmospheric chemistry, air quality and most importantly, global ozone recovery. In particular, I will investigate if macroalgae farms at high latitudes, such as the Canadian shelf zones, are less harmful to the ozone layer than farms in the tropics. Second, my research will focus on future shipping activities and their impact on the Arctic environment. Current climate change leads to dramatic melting of sea-ice, opening the Arctic for economically feasible shipping of cargo and tourisms. Increasing traffic will bring much larger emissions of exhaust gases and particles to the Artic, enhancing air pollution and impacting climate. In addition, these emissions will impact the Arctic Ocean by adding nutrients to the marine environment, thus influencing oceanic production and ecosystems. This work will investigate the impact of future Arctic shipping emissions on air quality and oceanic nutrient supply. In particular, this study will focus on shipping routes through and along the Canadian Arctic Archipelago and their environmental impact. Third, I will investigate anthropogenic pollutants that are emitted from industry, agriculture and wildfires into the atmosphere. I will focus on gases that remain in the atmosphere for less than 1-2 months, so-called short-lived climate forcers. These gases can either warm or cool the environment depending on the species itself, but also on the timing, amount and location of their emission. This work will quantify emissions of short-lived climate forcers, in particular from countries at northern mid- to high latitudes. As these gases play a large role for the Arctic environment, the emission estimates will provide important information on their climate impact.