Date of Award

January 2013

Document Type


Degree Name

Master of Science (MS)


Earth System Science & Policy

First Advisor

Rebecca J. Romsdahl


Nowadays the association between anthropogenic climate change and public health is in the early stages of universal recognition. Yet one fundamental aspect that remains largely unappreciated is the impact of climate change on ragweed (Ambrosia species) biology and the ensuing pathophysiology of human systems. Ragweed pollen is one of the primary causes of seasonal pollen allergy in the world. Allergic reactions to ragweed pollen can range from mild hay fever to life-threatening asthma attacks. The aim of this thesis was to conduct a ragweed allergy risk assessment for the Grand Forks ND-MN Metropolitan Statistical Area (MSA).

The study area is part of the Northern Great Plains, a region of short- and mixed-grass temperate grasslands, and is the native habitat for the most allergenic of the ragweed species. Through a ragweed habitat suitability modeling, it was discovered that 0.94% of the Grand Forks MSA was of high suitability for ragweed growth, 54% of medium suitability, and 35% was of low suitability. Overall, only 10% of the region was classified as not suitable for ragweed growth. The total ragweed potential increase for the whole MSA between 2000 and 2010 was 10%.

To examine the prevalence of ragweed allergies in the study region, a survey was conducted on students attending the University of North Dakota. According to the survey, 24% of the population sampled was allergic to ragweed. The ragweed-allergic respondents experienced all of the common symptoms related to ragweed allergies such as hay fever and asthma in addition to other symptoms such as vocal cord dysfunction and nose bleeds. Over 89% of the ragweed-allergic respondents admitted to allergies having an impact on their quality of life. Thirteen percent of the ragweed allergy sufferers (and all 6 of those originally from rural areas) did not develop allergies until they moved to the study region and had been living there for about 2 years.

Due to climate change, we can expect an increase in incidence of allergies in the coming years. Whereas climate change for the study region is not predicted to induce dangers such as hurricanes and heat waves by 2050, an upsurge in allergenic diseases can be forecasted. By 2050 we can expect a 9.6% increase in existing ragweed biomass and pollen producing stems due to increased temperature alone. Moreover, as the CO2 emissions of the study region are projected to rise by at least 50%, we can expect a subsequent 50% escalation in the amount of pollen being produced and released by ragweed plants.