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  • These spiny spheres are plant pollen, as seen under a microscope.


  • They're the culprit behind most seasonal allergies.


  • Pollen can cause your immune system to kick into overdrive because your body sees the pollen as a harmful intruder.


  • As a result, the body produces histamines.


  • Normally, they promote healing by increasing blood flow and inflammation.


  • But they can lead to the nasty symptoms we associate with allergieslike sneezing, runny noses, and watery eyes.


  • Generally, people who suffer from allergies have it bad for several weeks during certain plants' growing seasons.


  • But because of climate change, the level of pollen in the air is getting much worse.


  • And that's bad newswhether you suffer from allergies or not.


  • In order to grow and produce pollen, plants need to generate energy through photosynthesis.


  • That requires water, sunlight, and a third necessary ingredient, carbon dioxide.


  • Carbon dioxide exists naturally in the atmosphere.


  • But as we burn fossil fuels like coal in power plants or gasoline in our cars, we're putting more and more CO2 into the air.


  • The more carbon dioxide there is in the air, the more plants grow and produce pollen.


  • Take a look at this graph.


  • These bars are the level of carbon dioxide in the atmosphere between 1996 and 2015.

    這些長條是 1996 到 2015 年之間,二氧化碳在大氣中的濃度。

  • And this line is the amount of pollen produced per ragweed plant, a common source of allergens.


  • As carbon dioxide increased, the ragweed produced more and more pollen.


  • And pollen is an important part of a plant's reproductive cycle.


  • So more pollen means more seeds, which means more plants producing more pollen the following season.


  • But CO2 is increasing the level of pollen in another way as well.


  • Carbon dioxide is a greenhouse gas.


  • And it's called that because it traps the sun's heat energy in the Earth's atmosphere and is helping warm the planetsort of like a greenhouse.


  • As the climate warms, there are more days above freezing, which means more time that plants are active and producing pollen.


  • This graph shows the number of days with above-freezing temperatures in the US over the past 120 years.

    這張圖表指出美國在過去 120 年來溫度高於冰點的天數。

  • In the past 50 years, the US growing season has increased by over 10 days, on average.

    在過去 50 年,美國的生長季平均增加了 10 天。

  • And this isn't happening at the same rate everywhere.


  • This map shows the increase in pollen season for ragweed between 1995 and 2015.

    這份地圖顯示在 1995 到 2015 年之間,豚草花粉散播之季節的增長。

  • While some places, like Texas, didn't see much change in their ragweed pollen season, most placesespecially those in the northern US and southern Canadasaw pollen season increase by almost a month.


  • And this isn't just happening in North America.


  • Overall, most places around the world are seeing longer growing seasonsand, as a result, more days with pollen as well.


  • Pollen levels and allergies are only going to get worse from here if carbon emissions continue the way they are.


  • This is the current production level of grass pollen, another common allergen source.


  • By 2060, that level is expected to double.

    到了 2060 年,它的濃度預計會是現在的兩倍。

  • And by 2085, that amount will have more than tripled.

    到了 2085 年 則會成長到三倍。

  • While allergies can be annoying for the 1 in 5 Americans that suffers from them, they can usually be kept at bay with over-the-counter drugs.


  • But in some, allergies can lead to severe reactions like anaphylaxis, where blood pressure drops and airways start swelling shut.


  • And pollen grains can wreak havoc on people's lungs, even if they don't suffer from seasonal allergies.


  • In the US, asthma attacks induced by pollen have led to more than 20,000 emergency room visits per year.

    在美國,每年都有20000 人因花粉引起的氣喘送急診。

  • So if for no other reason than to protect your sinuses, it's important to reduce the amount of CO2 we're adding to the atmosphere.


  • It can help curb how much we're warming the planet and it can help slow the pollen apocalypse.


  • If your best strategy to avoid seasonal allergies is to stay indoors all spring,


  • then you might want a way to stay connected and that couldn't be easier to do from the safety of your pollen-free bunker.


  • Hover makes it simple to buy interesting domains with great extensions like .earth or .space.

    Hover 可以讓你輕鬆買到有趣的網域名稱,像是 .earth or .space.,而且還可以擴充。

  • Even if you don't need your own domain, you could set up a costumed e-mail address like ""

    就算你不需要自己的網域,也可以客製自己的電子信箱,像是「[email protected]」。

  • And right now you can get 10% off of your first purchase by going to

    如果你是第一次在 購買,就可以享有 9 折優惠。

  • Hover doesn't impact our editorial, but their support makes videos like these possible.

    Hover 並沒有影響我們的編輯自主權,但是因為有他們的支持,我們才能夠製作出這些影片。

These spiny spheres are plant pollen, as seen under a microscope.


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B2 中高級 中文 美國腔 Vox 花粉 二氧化碳 植物 產生 濃度

哈啾!惱人的過敏怎麼越來越嚴重?全球氣候變遷竟是意想不到的元凶!(Why your allergies get worse every year)

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    Vivian Chen 發佈於 2019 年 07 月 08 日