In the words of Cantarel et al. (2011), nitrous oxide (N2O) is "an influential greenhouse gas," with a per-molecule global warming potential "approximately 300 times that of CO2 (IPCC, 2001)," and they say it "has shown linear increases of 0.2-0.3% per year over the last few decades, largely as a result of changes in agricultural practices and direct emissions from agricultural soils (IPCC, 2007)." As a result, understanding the factors that control the concentration of N2O the atmosphere, and how the sources and sinks of N2O vary with changes in climate and other factors, has long been an important concern among the scientific community. And in this Summary, therefore, we review important research that has been conducted on this topic, beginning with a discussion of studies examining how increases in atmospheric CO2 might modify the release of N2O into the atmosphere.

As the atmosphere's CO2 concentration continues to rise, most trees will likely exhibit increased rates of photosynthesis and biomass production, which can subsequently lead to an increase in the amount of timber that will likely be required to meet the growing needs of earth's expanding human population. However, some individuals have predicted that CO2-induced global warming will counteract the growth-promoting effects of atmospheric CO2 enrichment and actually reduce tree growth. Therefore, in order to determine if this widely-trumpeted claim has any validity, we turn to the peer-reviewed scientific literature to both report and summarize the results of several CO2-enrichment studies that were designed to reveal the concurrent effects of elevated CO2 and air temperature on the growth of trees and other woody plants.

So far, the climate sceptics are right, the cry-babies wrong.

Writing as background for their work, Kaspari et al. (2011) state that "black carbon (BC, the absorbing component of soot) produced by the incomplete combustion of biomass, coal and diesel fuels can significantly contribute to climate change by altering the Earth's radiative balance," noting that "BC is estimated to have 55% of the radiative forcing effect of CO2 (Ramanathan and Carmichael, 2008)," which is in line with the approximately 1 Wm-2 radiative forcing of black carbon reported by Hansen (2002). Nevertheless, and in spite of these facts, Kaspari et al. note that BC still remains "one of the largest sources of uncertainty in analyses of climate change."

The IPCC is claimed by some to have provided evidence that the earth’s climate is harmed by changes in the atmospheric concentrations. of greenhouse gases. These claims are false. This report explains how dubious observations and some genuine science has been distorted and “spun” to support a global campaign to limit human emissions of certain greenhouse gases which has no scientific basis and no proven capacity to forecast future climate.

As the air's CO2 content rises, most plants exhibit increased rates of photosynthesis and biomass production (see our Plant Growth Database), which should enhance the amount of food, fiber and timber production that can be utilized to feed, clothe and shelter earth's expanding human population. However, some individuals have suggested that the growth-promoting effects of atmospheric CO2 enrichment may be largely negated by the global warming that is predicted to occur in the near future by a number of state-of-the-art climate models, which outcome could compromise our ability to sustain a greater human population without increasing arable land acreage. Thus, we turn to the scientific literature to see if plants will - or will not - continue to exhibit CO2-induced growth increases under conditions of predicted future warming, which we do here by reviewing what has been learned about the photosynthetic and growth responses of CO2-enriched agricultural crops grown at both current and projected future growing-season temperatures.

Atmospheric methane's contribution to anthropogenic climate forcing is estimated to be about half that of CO2 when both direct and indirect components to its forcing are summed (see Figure 1, below); and nearly all models project atmospheric methane (CH4) concentrations will increase for at least the next 3 decades, with many of the scenarios assuming a much larger increase throughout the 21st century. A quick fact-check, however, reveals that observations lie far below the model projections, as shown in each of the four prior Assessment Reports of the IPCC. So what has caused the IPCC to get things so wrong?

We begin this review of the Sun's influence on European temperatures with the study of Holzhauser et al. (2005), who presented high-resolution records of variations in glacier size in the Swiss Alps together with lake-level fluctuations in the Jura mountains, the northern French Pre-Alps, and the Swiss Plateau in developing a 3,500-year climate history of west-central Europe, starting with an in-depth analysis of the Great Aletsch glacier, which is the largest of all glaciers located in the European Alps.

The study of extraterrestrial climatic forcing factors is primarily a study of phenomena related to the Sun. Historically, this field of inquiry began with the work of Milankovitch (1920, 1941), who linked the cyclical glaciations of the past million years to the receipt of solar radiation at the surface of the Earth as modulated by variations in Earth's orbit and rotational characteristics. Subsequent investigations implicated a number of other solar phenomena that operate on both shorter and longer timescales; and this summary reviews the findings of the subset of those studies that involve galactic cosmic rays (GCRs).

As an Expert Reviewer for the Fifth Assessment Report, 2013, and in accordance with the IPCC Protocol for Addressing Possible Errors in IPCC Assessment Reports, I am writing to report a serious inaccuracy in the contribution of Working Group I to the Fourth Assessment Report, 2007. As a result of the inaccuracy, one of the report’s central conclusions was inappropriately drawn. The inaccuracy could have been avoided in the context of the information available at the time the report was written. It does not reflect new knowledge, scientific information, additional sources or a mere difference of opinion. I request that the inaccuracy be corrected and the correction published in the Errata for Working Group I’s contribution to the Fourth Assessment Report. No such correction currently appears in the Errata.

Anyone who has met Roy Spencer knows him to be a careful, thoughtful, unpolemical scientist of formidable skill and knowledge. With John Christy he presents the monthly real-world data from the microwave sounding unit satellites that provide the least inaccurate global temperature record we have.

The satellites reveal the inconvenient truth that there has been no global warming for approaching two decades.

This summary updates Monckton of Brenchley (2013), read at the World Federation of Scientists’ 2012 Seminars on Planetary Emergencies. The paper applied inter-temporal investment appraisal to mainstream IPCC climatology by comparing the cost of Australia’s 10-year CO2 tax (Parliament of Australia, 2011) with the benefit in the cost of warming-related damage the tax might avoid.

The claim that anthropogenic greenhouse gas emissions have been responsible for the warming detected in the twentieth century is based on what Loehle (2004) calls "the standard assumption in climate research, including the IPCC reports," that "over a century time interval there is not likely to be any recognizable trend to global temperatures (Risbey et al., 2000), and thus the null model for climate signal detection is a flat temperature trend with some autocorrelated noise," so that "any warming trends in excess of that expected from normal climatic variability are then assumed to be due to anthropogenic effects." If, however, there are significant underlying climate trends or cycles-or both-either known or unknown, that assumption is clearly invalid.

Was there a Medieval Warm Period somewhere in the world in addition to the area surrounding the North Atlantic Ocean, where its occurrence is uncontested? This question is of utmost importance to the ongoing global warming debate, for if the Medieval Warm Period is found to have been a global climatic phenomenon, and if the locations where it occurred were as warm in medieval times as they are currently, there is no need to consider the temperature increase of the past century as anything other than the natural progression of the persistent millennial-scale oscillation of climate that regularly brings the earth several-hundred-year periods of modestly higher and lower temperatures that are totally independent of variations in atmospheric CO2 concentration. Consequently, we here review the findings of several studies that have found evidence for the Medieval Warm Period in a region that is as far away from lands bordering on the North Atlantic Ocean as one could possibly get, i.e., Antarctica.

Using assumptions based on the Intergovernmental Panel on Climate Change (IPCC) Assessment Reports*, if the U.S. as a whole stopped emitting all carbon dioxide (CO2) emissions immediately, the ultimate impact on projected global temperature rise would be a reduction, or a “savings,” of approximately 0.08°C by the year 2050 and 0.17°C by the year 2100—amounts that are, for all intents and purposes, negligible.

One of the projected consequences of CO2-induced global warming is an increase in all types of extreme weather, including storms. A good test of the validity of this hypothesis comes from evaluating trends in storminess over the period of time when the Earth was recovering from the global chill of the Little Ice Age and transiting into the Current Warm Period, when the world's climate alarmists contend the planet experienced a warming that was unprecedented over the prior one to two millennia. In the present section, these claims are evaluated as they pertain to storms over of the North Atlantic Ocean.

Based on computer model projections, climate alarmists are concerned that global warming will usher in a period of more frequent and intense drought. Such concern is herein investigated as it pertains to the eastern portion of the United States.

Among the highly publicized doom-and-gloom scenarios that climate alarmists allege to attend the ongoing rise in the air's CO2 content are predicted increases in the frequency and severity of storms. As a result, and in an effort to determine if these predictions have any validity, many scientists are examining historical and proxy storm records in an attempt to determine how temperature changes of the past millennium have impacted this aspect of Earth's climate. This summary reviews what some of them have learned about various storm trends across North America.

In response to an increase in mean global air temperature, the world's climate alarmists contend there will be more frequent and stronger extremes of various weather phenomena, including what would seem almost assured: more frequent and extreme high temperatures and heat waves. But is this really so?

Climate alarmists contend that rising global temperatures lead to more severe and longer-lasting droughts on the basis of projections of global climate change produced by mathematical models that are primarily driven by increases in the atmosphere's CO2 concentration; and with respect to the western United States, there has been growing interest in understanding drought in that part of the country in light of the pronounced impact it has had there in recent decades. Therefore, many scientists have conducted research to attempt to better understand the characteristics of historic hydrologic variability in this important region, so that a more proper evaluation can be made of how unusual, unnatural or unprecedented droughts of the recent past have been, which droughts climate alarmists typically claim have been made worse - or even been entirely caused - by CO2-induced global warming. In the following pages, this claim is evaluated by reviewing what scientists have learned in this regard from various studies that have examined historic droughts across the western United States, organizing our review into several sub-domains within the overall region of study.

The United States' Northern Great Plains is an important agricultural region of North America, providing a significant source of grain both locally and internationally. Because of its location, it is also susceptible to extreme droughts that tend to persist longer than in any other region of the country (Karl et al., 1987; Soule, 1992); and because of this fact, it is a good place to review the history of drought to determine if the region is presently experiencing a manifestation of the climate-alarmist claim (Gore, 2006; Mann and Kump, 2008) that global warming will usher in a period of more frequent and intense drought.

Climate alarmists contend that global warming is responsible for creating more frequent and greater extremes of various types of weather. This summary investigates this claim as it pertains to precipitation variability in Europe.

Has the warming of the past century, which rescued the world from the extreme cold of the Little Ice Age, led to the yearly formation of more numerous Atlantic Basin tropical storms and hurricanes? This question is investigated here via a brief review of several studies that have broached this question with sufficiently-long databases to provide reliable answers.

Knowledge of the past is an important ingredient of any recipe for accurately predicting the future. If one desires to know how flood characteristics might change if the Earth continues its post-Little Ice Age warming, for example, it would be advisable to determine how these flood properties may have changed during prior periods of warming and/or cooling in Earth's history. Hence, we here review several studies of this nature based on data collected in Europe.

Climate alarmists contend that global warming is responsible for creating more frequent and greater extremes of various types of weather. This summary investigates this claim as it pertains to precipitation variability in Asia.