I am working with a table with multi-rows and headers. The problem is when I run it, extra space is added both between rows and at the end of the last column.
\documentclass{article}
\usepackage{geometry}
\geometry{a4paper}
\usepackage{array}
\usepackage{ragged2e}
\newcolumntype{P}[1]{>{\RaggedRight\hspace{0pt}}p{#1}}
\newcolumntype{R}[1]{>{\raggedleft\arraybackslash}p{#1}}
\newcolumntype{C}[1]{>{\centering\arraybackslash}p{#1}}
\newcommand{\head}[1]{\textsf{\textbf{#1}}}
\usepackage{tabulary}
\usepackage{booktabs}
\usepackage{multirow} % Allows rows in tables to be combined.
\usepackage{tabulary}
\begin{document}
\begin{table*}
\caption{Summary of studies examining MENA or OPEC oil export revenues under climate policies}
\begin{tabular}{@{}C{2.0cm}C{2.0cm}P{2.0cm}P{3.0cm}C{1.0cm}C{1.0cm}@{}}
\toprule
\ \head{Study} & \head{Time horizon} & \multicolumn{1}{c}{\head{Climate policies}} & \head{\centering {Uncertainties tested}} & \multicolumn{2}{c}{\head{Impact on oil export revenue}} \\
\midrule
\ \multirow{4}{2.0cm}{ABC} & \multirow{4}{2.0cm}{Results: 2025, 2050; Model: 2100} & \multirow{4}{2.0cm}{550 ppm \& 650 ppm GHG stabilization} & \multicolumn{3}{c}{\head{Middle East \& Turkey region versus the Baseline}} \\
\ & & & & 2025 & 2050 \\
\ & & & 550 ppm & -10\% & -20\% \\
\ & & & 650 ppm & -25\% & -35\% \\
\midrule
\ \multirow{2}{2.0cm}{CEF} & \multirow{2}{2.0cm}{2030} & \multirow{2}{2.0cm}{Global carbon taxes} & \multicolumn{3}{c}{\head{OPEC wealth versus no carbon tax}} \\
\ & & & Carbon tax (\$50/TC -- \$2500/TC) & -3\% & -63\% \\
\bottomrule
\end{tabular}
\end{table*}
\end{document}