If you look at the chart above you'll see that the amounts of pollen
ragweed produces only went up by 1 gram per plant in almost 20 years.
Not exact matches
This gets even worse the closer plants are to sources of carbon dioxide —
ragweed growing next to highways
produces more potent pollen than
ragweed growing away from large roads.
«It is also important to add that climate change consequences will not be restricted to
ragweed — and a range of other pollen -
producing species are likely to be affected.
When academic allergist Sanjiv Sur at the University of Texas in Galveston and colleagues exposed mice to
ragweed pollen, they noticed the animals
produced highly - reactive forms of oxygen in their lungs after 15 minutes.
The itching
produced by
ragweed allergy is the same as that
produced by oak pollen allergy.
They describe research showing that the quantity of
ragweed pollen
produced in doubled CO2 environments is increased significantly (61 percent), not because of large increases in size (~ 10 percent) but rather (apparently) due to a changing internal allocation of resources.
Ragweed, specifically, grew faster, flowered earlier, and
produced significantly more pollen in these urban conditions.
Now the Agricultural Research Service (ARS) has
produced a study into 15 years of pollen data, investigating anecdotal signs of an increase in the
ragweed pollen season - and whether it could be linked to climatic changes.